Sharee, I am sorry, life has had me away from the forum as much as I miss it and I didn't see your question until now.
I am not that experienced with intricate designs using MP, but there are some here who have more experience and may chime in.
What it looks like to me, is that the lighter colors of the waves were poured first, then let set up a bit before pouring the next layer. Alternating pouring the colors of choice for each layer with letting it set up a bit (just a minute or so, I think - depending on your base) then pouring your next layers. Spray with alcohol between layers to help each adhere.
Try a youtube search for MP tutorials of mulitiple color designs. I have seen some in the past, but don't think I saved any as I don't do a lot of MP myself.
BUT, I am interested in the less expensive price for the mold. If you don't mind, would you include a link?