I didn't notice it til I was taking pictures and video next to friends S5.. But, you can see it for yourself very easily.. Just point your camera at your TV and the TV Blacks will look Bluish on the G Flex.
Ah yeah the usage pattern matters. G Flex is a tad bluer and maybe more realistic, S5 tends to compensate and saturate colors. But probably if blacks on your TV are bluish on the Flex they are not true black. When all the lights are off, does black on your TV still glow a little?
I will post some images in a day or so when I get home, I got a flat screen with greyish blacks to test on. I have 4.4
And I do remember at least one reviewer claiming that sometimes too much blue was added. It seems they changed the software again with the G3 because some shots from it looked like they had a blown out red value.