What is color of orchid?

Since this is under home improvement/painting, I would suggest the simplest solution is simply to buy the color you want in the can. Seriously, you dont wan't to mix your own house paint! If you want to, for example, paint your name on a welcome sign for the front door, then you can get a small bottle of acrylic paint at a hobby/art supply store. Acrylic is very tough paint. From an artistic standpoint: The biggest problem to avoid in mixing your own orchid, lavender, or any color remotely purple is: Never use a red with yellow/orange in it, such as cadmium red. You want to use a 'blue' red, such as alizarin crimson, etc. Similarly you want to avoid a blue with yellow in it also, such as manganese blue. You might be better off with an ultramarine blue. The yellow in either cadmium red, or manganese blue will give you a muddy sort of brownish color. I would start with alizarin/ultramarine and add some white to lighten the intensity.