Why does the ink dries slower or faster depending on the color?
The paints, both those used at home and those used industrially, are simply surface coatings used to protect different types of materials.
The main components of the paints include: binders, which are the mentioned polymers and which provide the solid properties of the coating; solvents, which add the fluidity necessary for liquid deposition (can be water, hydrocarbons, alcohols, esters, ketones); the pigments that provide color and other additives capable of giving different characteristics to the deposited film.
So on the one hand we have the product, the painting. But to answer the question, we must also understand the application process, which generally has three stages. In the first one, the liquid paint is applied, afterwards it is subjected to a drying in which the solvent evaporates and finally it is cured, which is what we call the final process in which a chemical change occurs causing polymerization, a reaction that hardens the coating.
The drying-curing times depend on the type of paint and the way it dries.
If the drying is thermal, or what is the same, using heat by means of an oven or similar, the color of the paint does not influence the time necessary for said operation.
However, if the system used is ultraviolet curing, then the time required for this stage can be affected by the color of the pigment, since the different colors absorb this radiation in a different way. Darker colors need more curing time to achieve complete drying.
In addition, there are a variety of pigments: organic, inorganic, fluorescent, metallic, etc … and their properties are different. The drying time of a paint will also be different depending on the type of pigment.