When I design web sites for my clients, I always suggest a color pallet based on their individual business and preferences. If a company already has a logo then I work off that for a color pallet and work with the client to come up with a scheme that will work for them.

When selecting color, it is important to have some knowledge about the psychology of colors.  For example, one particular web site I looked at was offering self tanning products.  The color was sky blue with a mixture of black and white text.

The problem with the sky blue color is that is was cool and calm, not warm and inviting. A web site offering tanning products would need colors that are brighting, warm and inviting.  Colors that excite the web site visitor about the prospect of having a glamorous tan.

Whether is is your web site or the web site of your client be sure to have a complete grasp on what it is you want to convey without words with the colors you are displaying. Some colors excite the visitors to buy while others give them a sense of reassurance and trust.

It is up to the designer to explain these things to their client.  of course ultimately, it is still up to the web site owner to decide what they want.