How to choose a watercolor paint for fresh and vibrant mixes

When you buy a 5-10 euro tube of watercolor you want to be sure that this paint will serve you well in your palette. But how to choose the right one when you can't test it? How to predict if this paint will look good in mixes with other colors or not?

The main principle I use when I buy a new watercolor paint is counting the number of pigments. You just have to look closely at a pan or a tube and find the contents. What you are looking for is a letter P with other letters and numbers: like PB15:1, PB29, PG7 etc.

If you see more than one P on a tube, it means that the paint contents a number of pigments. These paints can be unpredictable in mixes as the golden rule is not to mix more than three pigments at once. When you see one P you can be more relaxed while mixing this paint with the others.