Your paint should dry to the exact color of the sample, if it does not, the color was mixed wrong. When you apply a fresh coat of the same color paint, it goes on lighter, and darkens as it dries.
NO ! -Use white to make grey lighter.
Latex paint weighs about eight to nine pounds per gallon. Oil base paint is slightly lighter. These weights are wet, when paint dries on a surface it will weigh considerably less.
Paint has two primary parts. The first is the pigment, which gives it the appropriate color. The second is the vehicle, which is either a type of oil, or water. When paint dries, the vehicle evaporates, leaving the pigment behind.
It gets all blury and the color will drip out.
It depends on the quality of the paint. Higher quality house paints dry darker while paints made only for coverage and price tend to dry lighter.
Include a white mixture to it in order to bright up the color
What dries fast is not so much the paint, but the fresh plaster on which the fresco paint is applied. And as the plaster dries the paint unites with it.
You will want to first paint the wall with primer paint. After that, if you are using a good quality paint for your light color, you can do it with one coat of paint. If it's cheap paint you may need 2 or 3.
maybe you should try it yourself.
Not without taking some steps. Your best bet will probably be to apply a layer of primer, then after it dries, the new paint.
Well,...in the Wizard of Oz they do...! Real paint horses may darken in the winter then shed back out to their original lighter color in the spring.