so simple to make - take s canvas, brush on some white paint as a base. you could use any other paint as a base depending of the colors you want, but if you want these colors like shown in the picture use white. While the base color is still wet, apply the blue color and just stroke the brush from side to side to create the blending. use a fair amount of paint to let the brush glide. if it dries dip the brush in some clean water.