Hi.
Ive worked with ocs(organic colour systems)since they were started which is over 10 years or so ago now.
They are gel based and the product range is from colour washes,crazy colours,semis.quasis,permanent tints,right through to hi lift.
They are ammonia free and theyre ppd level is alot lower than your average chemical colour.
The materials used to produce the colour products are certified organic aswell.
They have an organic perm and straightening system and a full range of after care and styling products,all plastic free and organic.
I would never use any other type of colour and cant recommend them enough.
Theyre factory is based in Lymington,the new forest and theyve also just opened a practical salon educational unit at the same location.
If you look on their website herbuk.com it will give you thier number.Give them a call.Theyre really helpful.
Hope this helps.
After 15 years in the industry i wouldnt use anything else.