if you have young children, acrylics can be too overwhelming for them to start with. Instead, I’ve found introducing watercolors first to younger kids meets them where they are at developmentally, especially if you give them only three colors (red, yellow, and blue) from which they can create their rainbow palette. While you can find inexpensive rainbow cakes of watercolor paint palettes for $5, those may also be too overwhelming to some kids, so stick to three and instead show them how they can create a beautiful world using a little time, patience, and just three colors.
There are several good instructional videos out there for techniques on how to begin children with this painting process, so here’s one that I found that might be useful. Enjoy!