I really like the way Kristof did his thing with 4 colors. So I tried to do something alike, but used some masking, to get a soft effect. Hope you like it. I can only try to get to the same level as Kristof ;-) stock image here.
Awesome idea...I just love it ! You just need a little bit more work with the execution, IMO.
I think adding a spectrum of color to the Roman Coloseum( misspelled, apologies ) is a fantastic idea, & softening the colors is on the right track...you just need to bring the colors down & have them not be so obviously linear. Have you spoken with Kristof ? He's a really nice guy & I'm sure he'd help you if you asked. Good luck & I'll be on the look-out for a repost !
Lauren