I'm sure the blue and red are voiced slightly different but the red is not only high gain. I ran it with gain at 1 o'clock and it was fairly crushing but you can back it off with the gain knob or the pedal cleans up really well with volume knob and touch sensitivity.
Put it this way. You can run the red with less gain but if you dime the blue and it ain't enough there ain't much to do but run the boost side! And then you've just lost your solo boost.
That's why red is the winner for me.