David,
I've played with dying materials before.
The real problem with it is the learning curve. If you have lots of material to 'practice' on, and the time to figure out the formula to get the exact color you want, then eventually you'll be happy with the results. If you aren't too picky, and just want a 'sort of chartruese' you can probably figure it out with a couple of batches. 'Really Bright' will be difficult, I'd think, but not impossible. They do have UV dyes available that wil give you a glow...
The folks that do this professionally have better dyes, more exactly controlled conditions, and the experience to get it done correctly without initially wasting more than a few hundred kilos of material.
Up to you if you want to expend the effort. There are quite a few tutorials available online that will help you get started and help shorten the curve.
Just be prepared for some failures.
Good Luck!
Buddy