The problem with using a computer screen to pick colors for real objects is that images on the screen project their own light instead of reflected light. The more intense you want the color, the more light you add. Add all the colors and you get white.
Dyes work by absorbing and reflecting light, so adding colors together absorbs more light, reflects less, and generally makes things darker. Add 'em all together and you (theoretically) get black.
Check out what StewMac calls "bright green" on maple:
http://www.stewmac.com/shop/Finishin...s.html#details
I'm not sayin' you can't come close. You might wanna look into fluorescent pigments, which actually shoot out new photons as others are absorbed. I'm not sure if they're ever used to dye wood, but it'd be something to look in to.