SUSIE'S REPLY: Hi Holly!
I'm happy to share my understanding of "warm vs. cool" with you.
Using a visual color wheel for reference; I believe the warmest color is red-orange and the coolest is blue-green. Let me offer this brief explanation:
- Both red and yellow are commonly considered warm, while blue is unquestionably cool. More specifically, warm and cool colors are relative to where a color falls on the color wheel. The warmest color is red-orange and the coolest color is blue-green. Everything between those two points has a slightly warmer color on one side of it and a slightly cooler one on the other. Its neighbor is either warmer or cooler depending on the direction you go around the color wheel.
- For my basic palette I use a split primary palette, working with a warm and a cool of each primary color. (WR/CR - WY/CY - WB/CB) All secondary hues are mixed from my carefully selected (split) primary colors.
When comparing any two colors of the same hue - one will probably be either warmer or cooler than the other. If you are comparing two yellow hues, the color with more red is warmer than the yellow with more blue in it. If you continue to move around the color wheel toward red the yellow turns into yellow-orange then orange then red orange before you get to the warm reds and to true red. [True red contains a tiny bit of both warm red (hint of yellow) and cool red (with a hint of blue.)]
If we continue around the color wheel we move from true red to the cool reds and move into the purples as we add more blue.
Blue hues are the most controversial ones! There are differing opinions about blue-greens being cooler/warmer than blue-violets and vica-versa.
I find for me personally it is easier for me to comprehend and understand if I look at the color wheel and see where a color falls. If it is closer to red-orange than it is to the blue-green then it is a warmer version of the hue.
Keep in mind.... "no matter what hue the color is, the color temperature (or the warmness or the coolness) of a color is relative to what you compare it too.
I'll be posting more thoughts on color theory. Click here to read "Some Thoughts on Color: Working with a Split Primary Color Palette" an article I wrote for "Inksmith" published by Daniel Smith.
Thanks for your question!