A few days ago, we were talking about different color labels on these Universal 4' rapid start ballasts. I just found one with a blue/yellow label. It could be blue/white, but I'm almost sure the white is faded yellow. You can see how the "Therm-O-Matic" writing is yellowed, but the Universal logo right above is white.

This ballast is also interesting because it is rated for 35 and 40 watt lamps, not 34's. It is full power, too, at .8 amps.

And it works!

-Nelson