Well, I have tried the cyan filter for several weeks. It is definitely brighter. I just put back in the blue filter. It is not as bright but bright enough and it looks so cool. I favor the less bright blue filter. Any filter is better than none.
I purchased a 2X20 display from eBay that came with a blue filter bonded to the glass. It works fine as a 2X16 display with 4 digits on the end not functioning. An escutcheon will fix that and only show the active digits. It was only $20.