Hello, all. I'm a Red Sox fan who is definitely pulling for the Jays in the East, but I also love going to ballparks. I've been to 30 (I still have five to see because five I've been to are no longer in use), so I registered to share my two cents on the park, which I went to twice when it was still SkyDome and generally enjoyed.
I think the Jays should keep the blue. Almost everyone else is green. Keep your identity. The color of the fences just seems a little different (lighter) than the color of the uniforms. I think the Blue on the unis really pops, and the fences should be made a little darker blue to match the jerseys.
But to me the biggest area to improve (besides going to grass, obviously), is the outfield. It's so boring. The walls are so high you may have one time a year when an outfielder robs someone of a homer, and then the balls just drop into a hole. I don't know if it was designed that way for football use, or storage or whatever, but when the Argos leave, the Jays have a real opportunity.
Maybe put in double-decker pens, like in Baltimore. Say those are in right-center, you can have seats behind the fences down the right-field line, and then seats behind the fences in all of left and left-center. Put slightly lower fences there, so outfielder can steal homers, and have seats there so fans can catch them. I think that would add a LOT of character.
Anyway, I'll leave you back to your team. Please hold off the Yankees! :-)