Ok so i recently purchased a old 2 channel dual rec figured i'd get new tubes got the yellows because i thought they would sound better then the greys. I was incorrect the yellows don't hold well at higher volumes the "tightness" of the sound really falls apart the louser i get. Now please keep in mind I have done enough forum reading about the color system of mesa tubes to make my head spin mostly on the boogie board. All i know is the colors from green to white handle louder volumes and still sound good for the music we play. My question is what is better for rock punk grunge crap we play. Green or grey even though they are only a little higher then yellows or do I go higher or do like 2 green and 2 blue and make purple haze lol anyway let me know what you guys think and please answer quickly i am doing the swap soon.