Looking for Some Natural Skin Dyes

I was referred to you by Barbra Dimitroff with these questions I have.
I have been looking for the following in any form, preferably dry: 1) cochineal, 2) madder, 3) betel, and 4) mangrove.
Maybe if I tell you my purpose it would help. I am a henna artist and am looking to redden the stain of my henna paste. I have done alot of research into this and know that skin dyes in a different way than cloth. However, I do know that some companies that produce henna paste are adding something to 1) darken and 2) redden the results. Some of them actually have managed to also decrease the amount of time the paste is left on the skin.
If you have any information at all as to where to obtain dye plants or something I might add to get the effect I am looking for would be much appreciated. I have been at this for some time now, and know that these companies are not willing to share.

We do not have in dry form any of the dyes you are looking for. We do offer two varieties of madder in seed and plant form, so you can grow these for yourself. We also carry henna seeds and plants which you can grow also. Cochineal is from an insect, by the way, which explains why we wouldn't have it.
I checked all the books on herbal and natural cosmetics in our collection but did not find anything specific on the subject of colouring skin. No doubt you are right in thinking that natural dyes are likely to work differently on skin compared to other media.
On fabrics such as wool and cotten, most natural plant-based dyes require mordants in order to hold the colour fast to the fibres. These mordants act as chemical bridges between the dye molecules and the fibre molecules. Without a mordant, most natural dyes will wash out too easily. Mordants also affect the colour: the same plant can yield entirely different colours with different mordants.
What the skin dye companies are doing to redden and speed up the dyeing process we do not know. This is likely to be a highly specifialized field and you would be best to consult with a chemist for ideas on where to look for clues. Start with a university chemistry department in your area.