EducationA guide to the colour of THC oil

A guide to the colour of THC oil

12 min read

Editorial Team

A guide to the colour of THC oil


The colour of cannabis oil can provide insights into not only the cannabis oil quality, but also some of its potential properties. When it comes to medicinal cannabis in the UK, cannabis-based medicinal products (CBMPs) have been legally prescribable since November 2018. Understanding the significance of the cannabis oil colour can assist in assessing cannabis oil that is of the best possible quality, and offers the greatest potential therapeutic benefits.

As the scientific community continues to delve into the chemical makeup of cannabis and cannabis oils, we all get to learn a great deal more about why cannabis oil looks and behaves the way it does. But this research isn’t done just for the fun of it. Clinical researchers want patients to be best informed about the available UK cannabis products, their effects, and how long they will be noticeable. 

Cannabis oil science has gone through an incredible journey in the past 20 years. During this period, a vast array of extraction methods have been developed and refined. Some of these processes have been further fine-tuned using existing methods already employed in other industries, such as brewing and scientific distillation. 

Some of these methods are basic, need little in the way of know-how, and can be achieved using household kitchenware. Others require expensive technical and pharmaceutical-grade equipment, and can only be done by highly trained technicians. This

The colour of the final cannabis oil product will depend on the process taken. Let's have a quick look at some of the processes used to make cannabis oil.

The different THC oil extraction methods

With cannabis science making huge leaps in the past 20 or so years, numerous extraction techniques have been developed for producing cannabis oils. These methods range in added complexity and sophistication, as well as the type of equipment required.

Apart from THC oil, CBD oil is another very popular therapeutic option that patients are increasingly adding to their current treatment plans. 

Alcohol/Ethanol cannabis oil extraction

Cannabis oils dissolve in solvents, and one of the most natural of these solvents is ethanol. Ethanol is capable of stripping the plant material of all fats, waxes, and lipids as well as all cannabinoids. The temperature will play a role in how pure an extract can be, with low temperatures reducing non-cannabinoid compounds that get extracted into the solution. The alcohol is then filtered to remove any particulate matter and evaporated to leave a thick, sticky crude oil. The lower the temperature of the extraction phase, the lighter the colour of the resulting oil will be.

Ideally, both ethanol and alcohol cannabis extractions will be golden brown. If they are green, it can be a sign that the cannabis oil chlorophyll content is high, which is less than desirable. Chlorophyll is a major factor in how ‘harsh’ cannabis oil may be when administered through a vaporiser. It also adds to the ‘earthy’ flavour, when used in food or drinks.

Heat is required to evaporate the alcohol from the solution. This can have an impact on the cannabis oil purity, changing it slightly from how it appeared when still on the plant. You can test this by putting a small dot on a piece of paper or a plate and wiping it to the side, revealing a streak where you can see the colour.

CO2 cannabis oil extraction

High-pressure carbon dioxide extraction is one of the most utilised extraction methods in the pharmaceutical industry.This process is named supercritical extraction and has been used to extract caffeine from coffee beans since the 1970s.

Pharmaceutical cannabis oil extraction allows the cannabis oil to be removed from the plant material without altering the chemical structure, resulting in a product that is as close to being a “pure cannabis extract” as possible and leaving no risk of impurities. You can see why it is a favoured method of extraction for the pharmaceutical industry.

Butane/Pentane/Hexane/Hydrocarbon cannabis oil extraction

Different hydrocarbon gases play different roles in extracting elements of the cannabis plant in a way that leaves behind things like pigment which may be unwanted. Some extraction labs in the US use a blend of up to five different hydrocarbon gases in different ratios in order to achieve the perfect cannabis oil concentrate. 

Due to the high pressure and flammable nature of hydrocarbon gas, this process is extremely dangerous and needs to be carried out in certain special safety environments. Once the trichomes have been extracted from the plant, the cannabis oil needs to be purged using a vacuum chamber so that it is just pure oil and no gas is left. 

This method is often referred to as BHO extraction or Solvent Extract. The colour should be from a light golden yellow to dark orange. A clearer consistency and thinner viscosity mean that fewer waxes and lipids are present, which means there is a higher purity of cannabinoids within.

Ice Water or Dry Ice 

With roots reaching back to the early days of western hash making in Amsterdam in the late 60s, ice water cannabis extraction uses iced water and micron filtration screens or bags, which results in cannabis trichomes extraction. The brittle resinous trichomes (that contain the vast majority of cannabinoids, terpenes, and flavonoids) break off in the cold exposure and sink to the bottom of the water. 

This water is then strained through different-sized micron screens in order to separate the trichome heads from the plant material. Once collected, it must be dried to remove the water. What is left are clumps of trichome gland heads, which contain the cannabinoids and other medicinally active compounds found in cannabis.

This method of extraction can also be achieved by replacing the ice water with dry ice. When done in this fashion, the process is simplified, as the trichomes simply snap off of the plant material and filter through the micron screen. There is no drying process needed. 

Dry Sift

Another ancient and traditional method of extracting the trichome heads from cannabis plants is to dry sift it out. This is most famously known as hashish, which comes from the Middle East, from Morocco to Afghanistan and beyond. Hashish production involves beating and shaking the dried cannabis flowers in screen bags, resulting in the trichomes separating from the plant material, which are then collected in an outer collection bag. The resulting trichome powders and small bits of plant matter are then pressed into blocks or balls – called hash – for distribution.


This new method uses old tricks to create a popular product. Taking raw cannabis flower, Ice Water/Dry Ice or Dry Sift hash and placing it in between two sheets of baking or parchment paper, or silicon sheets, to be applied with heat and pressure for a set time allows a simple mechanical extraction process. 

Temperature and pressure will play a role in the quality and colour of the end product. The lower the temperature, the lighter the oil will be.

Factors that can affect the colour of the final cannabis oil product


The lower the temperature of the extraction process, as well as the storage of the cannabis before extraction and the storage of the THC or any other type of extracted cannabis oil, the lighter the colour of the oil will be. If the temperature is higher than recommended for any of these stages, the oil may become darker and less desirable.

Age of the plant

As cannabis plants mature, the trichomes produced will also age and change colour. This can affect the colour of the final extracted THC oil, as well as its potency. When trichomes age, they go through a process where the cannabinoid THCA is converted into CBNA, which produces a slightly different effect and can also influence the colour, with the resulting extracted cannabis oil taking on a slightly redder hue.

Extraction method

As we have gone over above, the cannabis oil extraction method used can greatly alter the colour of the final product. Different methods extract different compounds, and some may result in a more concentrated or pure oil than others.

Filtering process

The level of filtration used during the extraction process can also have an impact on the colour of the final product. The more thorough the filtering, the lighter and purer the resulting oil will be.

The clarity of cannabis oil can be decreased by the presence of other plant extracts such as fats, waxes, and lipids. They make the oil appear more opaque or cloudy. High-quality cannabis oil that has been filtered correctly will have low levels of these inferior ingredients and allow some light to pass through to reveal the golden or amber colour.

Storage conditions

Proper storage is crucial for maintaining the colour and potency of cannabis oil. Exposure to light, heat, air, and moisture can all contribute to changes in colour and potentially affect the quality of the oil. Properly sealed containers stored in a cool, dark, and dry environment will lead to the best preservation of cannabis pigments and potency.

Harvesting methods

How cannabis plants are harvested can also play a role in the final colour of the extracted oil. Hand-trimmed plants that have been handled with care will result in less damaged trichomes and a more vibrant, golden-coloured oil.


The amount of time that is taken to extract the cannabis oil if a solvent is being used can impact the colour of the oil.


Cannabis oil oxidation occurs when the oil is exposed to oxygen. This can cause changes in colour and consistency, as well as potentially decreasing the potency of the oil. Proper storage and handling can help reduce this risk.


Naturally occurring cannabis pigments can play a role in the colour of cannabis extract. Anthocyanins for example can give a red or purple hue to cannabis oil, which happens with certain strains that contain high volumes of it.

THC oil colour and extraction FAQs

What does the colour of THC oil (and other extracted cannabis oils) indicate about the quality?

The colour of cannabis oil can be a significant indicator of its quality. Different shades can reflect the purity, concentration of cannabinoids, and the extraction method used. Lighter colours often signify higher cannabinoid and terpene purity and quality, especially in medicinal cannabis products in the UK.

How have extraction methods evolved over the years?

Over the past two decades, cannabis oil extraction methods have advanced significantly. Techniques range from basic methods using household kitchenware to sophisticated processes requiring pharmaceutical-grade equipment. These methods impact the final colour and quality of the oil. 

All medical-grade cannabis oils offered to Releaf patients have been extracted in lab settings using only the highest quality equipment and extraction methods

Why is temperature control important in the extraction and storage of cannabis oil?

Temperature plays a crucial role in the extraction process and storage of cannabis oil. Lower temperatures during extraction generally result in a lighter-coloured, purer oil. Similarly, proper storage temperatures are essential to maintain the oil's potency and prevent a faster onset of cannabis extract oil oxidation degradation.

How can I make an informed decision about taking medicinal THC oil?

Staying informed about the different extraction methods, the significance of oil colour, and proper storage practices is key. Understanding these aspects helps in choosing the right cannabis oil product for your needs, ensuring quality and effectiveness. 

In the UK, you can only legally access THC oil through a medical cannabis prescription. The prescribing doctors here at Releaf will be able to help you find the best possible cannabis-based medical products for your unique and specific health requirements.


So there you go, a complete overview of why THC oil can come in a range of colours, the various methods used to extract cannabis oils, and how each can affect the final product. Understanding the different factors that can influence the colour and quality of cannabis oil is important, as while your prescribing doctor will always offer high-quality cannabis oil extracts, knowledge is power - and this couldn't be more true for medical cannabis patients.

If you need medical cannabis to manage your health condition, Releaf has the resources to help. Our monthly packages are based on your cannabis prescription, and we offer specialist consultations for medical cannabis and a unique UK medical cannabis card for protection.

It is important to seek medical advice before starting any new treatments. The patient advisors at Releaf are available to provide expert advice and support. Alternatively, click here to book a consultation with one of our specialist doctors.

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Editorial Team

Article written by the Releaf Editorial Team, a group of seasoned experts in cannabis healthcare, dedicated to enhancing awareness and accessibility in the field through their wealth of knowledge and experience.

Our articles are written by experts and reviewed by medical professionals or compliance specialists. Adhering to stringent sourcing guidelines, we reference peer-reviewed studies and scholarly research. View our editorial policy.

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