There is no color that will make people spend money. It's the value of what you're selling, and the benefit they expect to get from the purchase, that will get them to spend money.

Why not reframe the question and ask, "What important consumer need can I satisfy that will be so remarkable that people will want it and pay for it?" When you get that, you can use whatever color on the walls you want.

Depends on what you're selling. For instance, black would be a terrible color if you have a flower shop, but would be great if you were selling clothing to the Goth community!

Candy its a great question and one of the many that are constantly explored in terms of shop design and store layouts and arguably onwe of the key things is to think in terms of 'blocks' of colour rather than any one colour.

To that end, matching a colour scheme to representative of the product is usually a good starting point. So for instance, a 'green' approach when selling gardening products is smart, BUT you don't have to have the WHOLE place green, just an area the emphasises the products.

Same goes with kitchens.

In fact the stores that surprisingly have the most difficulty are paint shops because they stick with the tried and true colour chart walls (which works) but they miss the opportunity to go with a big and bold theme, instead relying on interior design magazines to come up with a trend which paintshops then follow.

There's lots of research available to gain more detail than what could be provided here