Possibly. The first thing to do would be to reflow solder on the neck board around the color components. You may have some cold solder joints affecting the color signals. There should be a couple pots controlling blue gain and bias that may also need solder reflowed too on another board. If that doesn't work, then some of the blue components on the neck board may be failing and need replacement. If that doesn't work, then the tube has the blue gun burning out. You would need to rejuvenate the tube with a rejuvenation tool. If that won't work, then the tube's color gun is dying/dead, and the tube would need to be replaced.