Hello there Sleepy Mouse, I am your Secret Valentine! I'm not sure if this is quite what you wanted, I'm thinking in hind sight that I made the colours a bit too vivid. I had a lot of fun making this though!
I started by extracting Allen, then making the background and matching the colours to Allen's clothes, but the end result was a bit pink, so I used a couple of gradients and such. I may have got a little carried away with the brushes too. At least there is some yellow and blue there as you requested ^^
I hope you like this regardless!
- - Also, I made you a bonus gift! ... For some reason I forgot this was an iWall valentine, so you have an eCard on the way too! Silly me.
Lyrics from [this song] <3