I am having this same issue on my Macbook Pro retina early 2015. It just started recently. Last year, I had my display replaced as there was an issue with the coating flaking off.
Since then, I've had issues with the screen being dimmer than it should be. Now, I also have the ghosting issue when I wake it from sleep, but it also happens for me in real-time as well. Blacks also look greenish. I use the "flurry" screensaver, and if I turn it on, the color strands cause visible ghosting against the black background. If I reset SMC and PRAM, it improves moderately, but returns every time I wake the MacBook from sleep.
I started noticing this when I began using Night Shift earlier this year. I've used f.lux for years before that, but decided to give Night Shift a try. f.lux had an issue with a lingering tint when color adjustment should have been off. Part of the fix was to turn off automatic brightness, so I turned it off and the issue went away completely. I'll be taking my MacBook in to Applecare next week to have it checked out.
