Dots with high flow acrylic paint.
Dots with gouache.
Blobs with gouache.
Brush marks with watercolor, changing colors ever so slightly.
Today's prompt is all about little tiny marks. What do you call these? A spot, circle, round shape, blot, blob, fleck, raindrop, tear drop, droplet, polka dot, point, mark, blotch, speck, particle, teeny tiny mark, dab, atom? Or perhaps translate that concept into your favorite language. Whatever you call them... make a bunch of dottical marks on a loose piece of paper or a page in your journal. This could also be a background for collage.
You could make repeating patterns, test different brushes to see the type of blots they make, or make dots with a variety of pens.