Are there any image enhancement modes you can try turning off or reducing? I'm wondering if edge-enhancement or anti-jaggy processing is causing this.
It reminds me of a technique used in video games since the early 80s to smooth the jagginess of diagonal white lines on CRTs. A pixel was 3 phosphor elements, RGB. All 3 are lit up to make a white pixel. But to make the white pixel look a little wider, without going to 2 full pixels, you could make the pixel on the left B, or the pixel on the right R. In the first case, you get BRGB. Your mind made this look like a slightly wider white pixel. This effectively doubled horizontal resolution for white objects and helped smooth out jagginess of diagonals. But, if it was done backwards: R__RGB, it just looked like a red dot off to the left of the white. Or RGB__B. I'm not saying something is being done "backwards". It just reminds me of this. Anyways, check and see if edge-enhancement is set too high. This can cause ghosting which maybe is showing up as these red and blue lines on a plasma.
Microsoft patented that technique to smooth fonts in the 90s. I remember thinking that's odd, since video games had doing this for 15 years. Whatever...
Panasonic TC-P60ZT60 plasma panel
Sony BDP-S5500 Blu-ray player
Arris DCX3600-M DVR
Yamaha RX-V650 AVR
URC MX-780 remote control