Hi curlyjocelyn – I used Lush Caca Marron about once a month. My hair is dark, so the color change isn't dramatic, but I like that it makes my hair feels smoother and gives it a lovely shine. After a henna treatment it almost feels like I've just gotten a haircut! Since henna behaves similarly to a protein treatment with the dye molecule bonding to the gaps in the hair's cuticle, your curls might spring up and shorten (or smooth out and lengthen a bit according to your pattern, I imagine). Although the cocoa butter in the Lush product makes for easy application, I remove my henna without shampoo (just conditioner) to give it extra time to bond to the hair and the butter weighs my hair down quite a bit. I do wash it out at the next shower and then we're back to the typically unweighted feeling. I'd recommend a moisturizing DT such as AOHR after you've washed out the cocoa butter, because it really does make a difference to soften the hair after henna.
Let me know if you have any other questions!
Hi Moonface – Do you remember what brand of Henna you used on your hair? I think (but may be incorrect) that the blue/green comes from the presence of metallic salts in the dye which are added to some "Henna" hair dyes, but aren't characteristic of quality Henna hair dye.