The title pretty much says it all, but ...
CS5.5, Windows 7 64-bit (just in case that's needed)
I have a layered PSD image. One layer is black (#000000). I flatten the image and sample the black area, and it is still pure black. I crop and resize the image - still black. I save as a jpg, and when I reopen the jpg, the black is no longer pure - (#010101). What gives?
It would appear it had something to do with the quality/compression setting. Turned it up (on a hunch) and the problem went away. =)
Yes, because JPEG is a lossy format, even solid colors can get changed slightly.