Thank you Becky, you're perfectly right, it was a "calculated snapshot", i.e. a shot taken very quickly, having foreseen the possible result. Pre-selected ISO was not enough to get a higher shutter speed and I just focused on capturing the image. Overall result is then OK. I'll pass your suggestion about repainting office walls to our managers, but I can't guarantee... All the best.
Hmmm . . . I'm not really sure what to suggest. It seems to me that this is a snapshot, which really doesn't give you a lot of time to compose a perfect shot. As a snapshot, I think it's quite alright - there's a nice sense of motion as the feeling of the "server" weaving through a crowd of people is captured nicely (which is why I don't mind the tilt/canted angle of the photo). I suppose you could have angled the camera up a bit, so as not to cut off the tops of heads, and a bit to the right, so the big arm in the foreground (on the left) isn't as prominent and distracting. As for the background colours, I think they're fine. The tones are nice and the exposure looks quite good (white or off white walls are easily over-exposed). If you're not happy with the colours, I'm not sure what to suggest, short of repainting the office walls! :)
I do feel that the shutter speed could have been a bit higher. That way, your subjects would have been a bit sharper, but again, doing so could lose the sense of motion through the crowd.