Recently, my displays have been turning blue when they wake up from sleep. This has hapeened on my Macbook and on my 2nd monitor on my PC (which I use for VM and remote desktop). It's possible that part of it might be my eyes, but seeing the blue monitor next to my other monitor on my PC has convinced me that something is probably out of place. What might that be?
Yes, bumped cable was going to be my first guess. Make sure both sides have a nice clean connection. If it still isn't working try a different cable. Visually examine the two ports see if you did any damage or any pins that are broken or stuck. You can't really "Short the red out" (that I know of), but for some reason it may not be making a connection.
Many video drivers allow you to make your screen "cooler" or "warmer"... perhaps your computer is set to cooler settings? Or perhaps your saturation is incorrectly set?