Man, your pages are so tight as they are! I really dig how clean and crisp everything is, looks amazing! I think you could totally work in some simple watercolour splash layers (set to overlay/soft light/hard light/etc.) over the backgrounds and adjust opacity to a delicate little touch. It might look really nice! Is that your plan or would you want to paint the backgrounds with a textured brush? Either way, you could experiment and get that look down, your colours are already fabulous.