Does YouTube Render Down Colour?

Hello,

Everytime I work on a video within Final Cut Pro, I do a bit of colour adjustments. Just a bit to boost the colours to get a little bit of contrast. When I render then export the video everything looks great but once I upload the video to YouTube the colour adjustments don't seem to have been applied or they got rendered down quite a bit. Does this happen to anyone else? The strange part is that I don't get this issue when I upload a video to YouTube that was edited within Adobe Premiere Pro CS5 and my work flow is exactly the same just different software is being used. Another strange thing is that this only happens with footage from my Nikon D90, none of this happens if I use footage from my GoPro Hero HD.

Here is a little comparison video that I made. Maybe I should do the same thing in Adobe Premiere Pro to see if there truly is a different or perhaps I'm just going crazy

http://www.youtube.com/watch?v=plijIgG84oM

What do you all think?

Thanks
Mike

When ready to export, the video format is MP4 in Premiere Pro CS4 and MOV in Final Cut Pro.

The color adjustment sometimes seems like it isn't applied at all or its just really dull.

I recently uploaded a little tulip video. I did one in FCP and another in Premiere. Both had colour adjustments but Premiere came out much stronger. After uploading both to YouTube and watching them side by side the dull FCP version looks better but only on some clips. Perhaps I need to master colour correction or maybe try out Magic Bullet Colorista or PhotoLooks.