Green, blue and purple are traditionally cool colors and red, orange and yellow are typically warm in nature. However, there are warm greens, blues and purples as well as cool reds, oranges and yellows. Knowing your color palette in regards to temperature will assist you in conveying the right mood for your painting.
Color can also trigger an emotional response. Advertising has used color in this way for many years. Artists can also utilize color to enhance a concept, appealing to the emotions. The color green, for instance, can communicate nature as well as a feeling of well-being. Yellow conveys friendliness while red can communicate heat, vigor and energy. Purple, on the other hand, is seen as a color of royalty in many cultures.
When making a choice about what colors to use, consider utilizing a controlled and limited palette. I like to use split-complementary colors. In other words, if my painting utilizes yellows in the focal area then I would use purples (both red violet and blue violet mixtures) in the appropriate tonal range to communicate just the right mood. This is typically done in a one third to two thirds ratio to create impact. To assist you in choosing the appropriate colors, I suggest you create your own color wheel using the tubes of paint that you own, labeling them as such on a wheel. This will simplify the color selection process.
Below is a great video on gamut masking by artist and illustrator James Gurney. He has a book out called Color and Light that is very insigtful when it comes to color.
You may also want to play with Golden Paint's Color Mixer