These colors are typically used with logical or technical material but aren't restricted to those categories. For instance, green is equally useful for environment, outdoors, active lifestyle and other activities like that. Blue is often used with water or electrical sites because of the color association between blue and ocean color or blue and lightning color. Warm Colors are used to connote emotional empathy or other positive emotive feelings. It has been used for passion as well.
Warm colors appeal to the heart while cool colors appeal to the head.
Pastels are used with arts and crafts as well as more sedate hobbies and pursuits. Pastels are non-intimidating and soothing, in contrast to Impact colors which are designed to attract and alert. Shades of Gray are often used with businesses because of the truly neutral nature of gray. Gray neither solicits interest nor deters interest - it merely is. A site intended mostly for information dissemination purposes would be one where Shades of Gray schemes ought to be considered.