I used to get colourshines for years too when I wore relaxed (straight) hair. Got the same colors as you're getting! I loved the back orchid but switched to coffee bean because sometimes my hair would look green under flourescent light.
I don't think this product is designed to cover grey hairs. It's really just a tint which is why it is also called a "cellophane", as in the plastic wrap.
You might consider getting a semi-permanent color. I've been using Color Charm semi permanent in Violet which is similiar to the Black Orchid in color but is more adherant to the hair. I have a lot of grey strands and they are coverered satisfactorily for about 6-8 weeks. The color washes out so it's easy to re-apply. You can wash it in and don't have to do just the roots as with permanent color. I haven't used it since I got a texturizer last month but I'm due for a application in a couple weeks. According to the label it is safe to use the same day as a relaxer and my stylist confirms this. I've used it on my natural hair for a few years and experienced no damage at all from it. As it washes out, the grey hairs are lighter than the rest of my hair but it looks sort of like highlights.
