Sure you probably have dump this idea (I totally get the art trip to find better ideas etc...like some of us here)...but honestly this one was looking so good 
And your colours are contrasting perfectly.
Of course painting on one layer is a master skill 
I really don't think many do that (or at best 3-5 layers)...sure I know Marc Brunet do this (maybe not all the time) 
Anyways, hope you can finish in time !
Best of luck.