I had set up a Website, these theme color is gray, the background is white. But customer's product color are variety, so it not looks very beautiful. Which color do you think can apply this model?
The website's colors should match just that - the website's colors. Your best bet is to use a neutral background - either white, black or some form of grey, so that it looks the same regardless of the product on top - have a look at eBay, for instance - the products offered are varied, but the site has a consistent look.
PoPSiCLe's right. Stick to neutrals as these will work regardless of the color of the products being sold. Pick the color carefully as you may turn away visitors and potential buyers with a bad color choice.
Suggestion is to be consistent with your color selection pal. Professional colors are white, grey and shades in blue normally but It also depends on the type of your business. If that is about some artistic work or children stuff it can colorful but for serious businesses variety of theme and colors will look unprofessional.