The background colors aren't as bad as they once were. Coming out of the lockout, the NHL went to a mandate that every dasher advertisement have a white background. Hence, it's not as garish and gives each arena a standard look. I think the distraction was worse when you had a red background, followed by a yellow one, then blue and white.
Some of the arenas are worse than others for ads. The Flames might be the worse of any of the teams. Calgary has the lighted up Rona sign behind the goalie that has to be taken down at the end of every period to let the Zamboni through - Im surprised players don't find it distracting since they are shooting right at a lighted billboard. Calgary also is one of the worse offenders with ads on the outside of the boards- just below the glass and ahead of the first row seats so they are clear to viewers during the entire television broadcast. That seems to be used in several of the Canadian arenas. Also many teams have the ads on steps. Depending on the colors, I find those quite garish and annoying. There's also ads on the first rows of seats which seems to be gaining in popularity.
If you went to green screens for all the dasher board ads, teams would lose some value, since nobody in the arena would see any of the advertisements. Also, you'd have to work out a revenue deal between the teams and each network. As far as I know, the only people making money off the virtual glass ads are the tv networks. They use them for extra revenue while the teams don't get a piece of it. Another thing to factor in is that it's not cheap. To set up, green screen technology is expensive, and I'm not sure the expense involved would make it worth it.
An interesting note about these virtual ads. Sportvision originally created this technology for the FoxTrax puck. They then branched out to using it for 1st down lines in the NFL. This led to virtual ads in MLB and for the Indy 500. Now the FoxTrax technology has come back to the NHL full circle.
