Hey im having some trouble with my bassman 70. One of my output tubes (6L6) isnt glowing blue when i turn my stand by switch off to play. The tube is glowing like the other just doesnt have the blue glow. They are new tubes with about an hour of playtime.What could be the cause of this?

Tubes can glow orange, yellow, red, or blue. Unless you start noticing sudden drops in volume, you'll be fine.
5150 combo
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ESP LTD M-255 w/ SD Full Shred
Kramer Vanguard w/ JE-1000 active preamp
Douglas WF-150sn w/ GFS "Hot Lead" set

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I believe a strong blue glow means that there isn't a complete vacuum in the tube. If it's just a little; nothing to worry about.