Here, let me show you something I talked about in snowcamp. Above are three notes of roughly equal value, one is yellow, the next red and the last blue ( barely, in this photo, but take my word for it). They are all mixed down with a lot of white. I am going to lay them loosely on top of one another and make a patch of broken, or divisionist color. Like so..........
The resulting patch of color has the three notes placed discreetly and separately. When we look at it, there is opalescence, or vibration. Vibratory color is much more alive then a simple flat note of paint laid like a housepainters brush stroke. I use vibratory color a lot in my painting because it enlivens passages. It is particularly useful in skies and snow, but entire passages and entire paintings can be made of vibratory color. This simple little effect is one of the roots of impressionist technique.
Nature is complex and the vibratory effect confuses the eye slightly and that recalls the complexity of nature as we see it, better than a flat color note would. There are other ways to do this, for instance, different shades of the same hue laid over one another in the same value.
Here I have divided the pile into two sections with my knife. To the right of that line I "licked" the paint until it was all blended together. It goes flat then. It is the color of pewter, dead. In order to work, the notes have to be separate from one another, discrete.
This is one reason that the old time painters cautioned so strongly against "licking". Licking is brushing repeatedly at your paint like a cat might lick it's fur. It muddies your color and wastes your time. Learn to put a note down and pull your brush away. The more times your brush hits a note, the weaker it gets. You cannot worry the paint on your canvas into a picture.