Now this is nice, it flows so well. Just like Piotrec said, the colour harmony is fantastic. This could be from a painting like what you might find on a cathedrals ceiling or something. Amazing!
As usual. Base off-white acrylic. Local oil filters for white spirit (Black + Sienna + umber + white). Dry brush the light and dark shades of the base colors. Lightening and darkening with a semi-dry brush poking.