After my update to Mavericks my mail won't open. It will open for 2 seconds and then crash every single time. Is it just me or should I just go ahead and do a clean install? Do I need to copy and paste my crash message here? 
I'm getting the same message as well. Luckily, I still have my phone to access mail. Such a bummer. Guess I'll wait until they send an update or something.I had this error:
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -redComponent not valid for the NSColor NSCalibratedWhiteColorSpace 0.25 1; need to first convert colorspace.'
Not sure if that's relevant.
I had a similar problem where mail was showing open with the indicator under the mail icon on the dock but no actual mail window open to view messages so i invoked a quick reboot which on restart did take longer than usual but touch wood so far the reboot seems to have sorted my issue.
Worth a try?
Open up terminal and try this:
defaults delete com.apple.mail ColorQuoterColorList
Open up terminal and try this:
defaults delete com.apple.mail ColorQuoterColorList
Domain (com.apple.mail) not found.
Defaults have not been changed.