rtrski

In one sense you have a point ... The display won't be clear as an actual backlit screen and limited in what you choose to put on it to be visible.

In another sense ... Yeah sorry its still cool as hell looking even for useless "ambience". Especially when well fitted over a bright white case interior.

Cut a thin piece of clear acrylic to cover the entire triangular area. It'll be raised so get the exterior outline right. Could even get someone like Ponoko.com to make it but will cost a bit. (Alternative...3d print inverted with a clear filament. Want the cleanest (build plate) face for the top.

Black paint top and sides after masking with a vinyl cut logo you can peel afterward. Or black paint then laser etch the logo. Suggest multi paint coats for full hide. Low wattage 1-10w blue diode lasers are plenty to "cut" black paint.

Sand the backside with fine sandpaper 400grit or so to make it a diffuser.

Tack glue it on with small dots of superglue well away from the actual light source area (after just holding in place to test and see if it lights up the way you hope).

Watched enough. The tabs coming out of the bottom of the switch are not magical. You don't need to use Spade slide connectors over them. You can solder to them. You can tie a wire to them at 5 volts for Christ sakes. The other end is standard motherboard pin headers.

Why would one source some sort of specialized cable just put a different case switch on to motherboard pin headers? If you don't already have an Electronics toolbox with all sorts of different bits and bobbins, it's a complete waste of money.

Please tell me you're kidding???

A PC power switch makes momentary contact on a 5v control signal. Any two wires will do.

You didn't say (that I saw) what case you have. Are you 100% fixed on it being off a 5.25 front bay? Could it be interior to the case, thru a side glass window instead?

That's what I did. That said, I also went wacky and had a brushed aluminum bezel with threaded posts made to my specifications, complete with engraved and ink filled markings for extra bling, and had to source drone HDMI flat ribbon cables to get the interface routed...

The site I got my bezels made might help you out too, but you'll have to take on the design yourself to come up with something with side 'legs' you can mount into a 5.25 bay. Frontpanelexpress.com , highly recommended, wonderful work, NOT inexpensive however. They can do threaded holes, inner and outer profiles, steps in the profile, slots, even threaded posts (male) and bosses (female).

I won't post gratuitous pics of my setup with internal screens, doesn't seem like what you're looking for. But if you search on my nick I'm sure you'll find them, if you wanted to.