I use the increase canvas size option a lot, just gotta crop you image to full size first and put your colored layer at the bottom, only thing I hate about it is if you use shapes to create a colored backdrop your have to go through and rastersize you layers first.
"If you get hit and it hurts hit him back you not knocked out yet."-Joe Doerksen
The Toxic Terrors (FFL)
Georges St. Pierre*Sarra McMann*Pat Curran*Patricio Freire*Uriah Hall
NP FFL Team Toxic Challenge
Fabricio Werdum*Gilbert Melendez*Rick Hawn*John Dodson*Urijah Faber