The Blues

Most students understand pretty quickly the difference between warm colors and cool colors.  Warm colors look like fire and the sun, and cool colors remind us of ice and snow shadows.  Warm = yellow, orange, earth tones and reds.  Cool = blue and green.

So when students hear that in the primaries there can be cool yellows and warm blues, they freak out!
For example, take the color blue.  Ultramarine blue is considered to be a "warm" blue because it leans toward the red side a bit.  Thalo blue, cerulean blue and manganese blues are all "cool" blues.  The purest blue is considered to be cobalt.

Why is it important to know these differences?  Look at the painting I did of a spring house in New Hampshire.  You'll see that in the distant mountains I used an ultramarine blue because the mountains are closer than the sky.  By contrast, I used a cerulean blue in the sky.  Remember the old maxim that warm colors advance and cool colors recede. If I had used the same blue in both places, there would have been no contrast, and therefore no differentiation in spatial distance.  I could have also used a thalo green in the sky to make the difference even more pronounced.

So don't always reach for the same blue out of habit.  Know why you are choosing one blue over another.