Blue (phthalo, cobalt, or cyan, primary)
Check out this paint set on Amazon
Add other colors/shades to have more options and versatility in color mixing. I use medium body student grade acrylics. I DO NOT recommend craft paint.
Large Square 1"
Medium Square 1/2"
Check out this brush set I recommend.
Optional extra brushes, pallet knife, sponges, circle shaped objects for moons and suns.