Personally I'm not a fan of white ... its too clinical for me. I used to work in a Health Centre where nothing was white ... not the woodwork or the ceilings.
Earthy neautrals and creams are calming and good.
How much of your clientelle do you expect to be guys? Don't forget to ensure your retail area reflects this, if you are expecting guys you don't want them walking in to be confronted by a huge nail polish display.
Really consider your retail display area, personally I think a shelving looks a lot more inviting then display units ... not a fan of the Dermalogica one for example. Guys are a funny bunch ... they don't want to ask questions so don't have all the products in cabinets, let them pick them up and look at them. Also think of the gifts market - a nice display of gifts for the lady in their life, or for the ladies to suggest to the man in theirs.
If you are expecting guys then look at adding a treatment such as Cut Throat Shaving with a suitable product range. And don't do what a local salon to me has done, invest in a really good shave company and range of products and then put them on the bottom shelf 6 inches of the floor! Quite frankly no product should be that low, remember if its eye level its buy level.
For the layout / decor of the holistic / beauty room think about dressing it. If you have some ladies who lunch clients you may dress it differently then for a guy for a sports massage. The paint colours are fixed, by dressing think how you lay the towels, display products to be used etc, put a decoration on the table for when they enter. This tailoring of the experience is one of those little touches that don't cost anything, but can really make the difference ... change a treatment into an experience.
Good luck!
Mat