This morning i turned on my TV and all pictures of humans look like I'm watching Avatar. All human coloring is in a blue-ish hue.
Can the cable box (FIOS) interfere with the coloring or is this more to do with my LED TV (Samsung).
The STB does nothing to picture color.
How is the STB connected to the TV? If it's using component connections then it sounds like one of the three wires is not connected properly. If the picture looks blue/green (like Avatar) then it would be the red component cable.
All the Avatars, of course look blue, but I have to assume you mean regular humans. Picture color normal on other channels? Usually hue and color are your TV but not always. If its not your TV. Make sure all connections are properly made. Missing, bad, or incorrectly connected component cables or pin contacts in HDMI can change color. And of course a defective set top box.