It seems that there is absolutely no way to get video colors to be the same on different browsers. I followed the Cow tutorial on color spaces and did an sRGB test project and every browser's colors measured differently. I used the Digital Color Meter on the Mac and something else one windows. Chrome even gave me different colors on different Macs! Is that basically the way it goes?
And as Dave could also tell you, if you've ever worked in NTSC color for broadcast, you quickly realize that the acronym means "Never the same color". Browser color matching is even worse! How many home (or even business) users do you know who calibrate their monitors? Colors will vary, and monitors will vary, and if you're working for a client who wants their logo colors matched, you have to make it clear to them up front that all bets are off when it leaves the view on your monitor.
@Joseph: I'm still a bit confused as to why monitor calibration should matter. If I use the color meter to measure the css colors, then I get the same readings. Why shouldn't a video with an embedded ICC profile give me the same readings? I get that one uncalibrated monitor will look different from another. And they often do even for css. But I don't get why videos should diverge. Actually, I originally thought this thread was going to be more along the lines of: Why is Firefox different? And indeed, it does seem to be the biggest outlier and it does seem to be the one getting the most complaints. But then I noticed that they all diverge. What often happens in browser land is often Chrome and Safari behave similarly since they are both webkit browsers.