Watercolour Brush Pens
I love these so much. They let you watercolour paint with less mess. This particular set that I have linked here I did by myself and they lasted for about six months before the pens started to dry out and lose their colour. You could also do just a regular watercolour painting set with the water brushes that come in the set, but I still love the set overall as a crafty kid.
https://amzn.to/4xltPyd