Purple color in CRT

[mbates14]

Well, i have a zenith PV800 front CRT projector, and the red tube glows both red and purple all across the neck of the tube as soon as HV hits the electrodes in the gun, and the main anode. Also you can see faint electrons/ions "raster like lines/image" striking the face of the red tube when the HV comes up before the filaments heat up.

But funny thing is, the red tube still projects, and a good picture at that. BTW I am in the cincy area.