Old GE 8mm camcorder-no color when pla...

Yes, this sounds like dirty heads, typical symptom for analogue 8mm.

Yes you can clean the heads. It's a delicate procedure, but, requires no disassembly. To clean your heads, I would run to Radio Shack and buy cleaning fluid refils. Take a Qtip and dampen it with the cleaning fluid. Open the camera, remove the tape and look for the video drum. Lightly rub the Qtip along the drum horizontal to the spin direction (not across the grain). Turn the drum and clean until you have swept the entire circumference.