Photos of tinted glass over a monitor are misleading (especially Oscar's), as they suggest it makes colors more vibrant, which is far from the truth. Photographing a monitor is difficult, it requires turning the flash off, which in turn causes the brighter non-tinted monitor to appear washed out, and the darkened tinted monitor ends up looking better.
Primarily, tinted glass is used to hide a screen-burned tube, a poor monitor installation, or a poorly fitting (or missing) bezel. If your cabinet doesn't fit into any of these categories, I'd suggest using clear Tempered glass.
Keep in mind that practically all newer monitors have a black/grey tint to the tube already. I have had problems with brightness with tinted plexi on some games with perfectly good, new monitors! I used tinted plexi on these games just because I have a BUNCH of it scrap (it was free).
I have a dozen games, and some have tint from the factory, some don't, and none that I have built have tinted plexi because in general, it doesn't look as good IMO. Generally, the older games had some light tint, and newer ones don't. The dividing line seems to be somewhere around 1990.
I've never felt I needed to "add tint" to a monitor. The best lighting for playing games is a dim ambient light, and under those conditions I haven't had trouble seeing the monitors or getting enough contrast out of the monitors. Tinted or not, when I have the overhead lights on in my gameroom, it is hard to see the monitors. Those lights are only on if I'm working on a game.
I know I'm in the minority on this forum on the tinted glass topic. :/
Wade