The backlight repair has nothing to do with replacing the bulb. I Googled it.
I even wrote a PowerPoint presentation on MODS.DK, on how to repair the backlight inverter.
You should correct / update that MODS.DK presentation, now that you have seen a cold cathode lamp,
and the video of its replacement.
As Scott, KD0REQ noted -- color gels work best.
Yaesu uses colored gel tubes and caps (green, red, orange) for a
number of their radios FT-102, FT-107, FT-2800m, etc.