I needed to solder a breadboard onto a PCB for another project, Jumperless. It seemed like someone should be selling just the spring clips they use to make breadboards (bonus points if they had little tabs that could be through hole soldered.) But no, amazingly I could not find anyone selling just the metal part without being encased in a plastic shell.
So I fired up Fusion 360, designed my own, sent out some sourcing requests to US-based spring clip manufacturers, got some quotes, wondered if they were smoking crack or I was on a really weird prank show (they wanted ~$20 PER CLIP, you need 80 of these ($1600) for a half-size breadboard), put up a sourcing request on made-in-china.com, got a bunch of non-ridiculous quotes, and eventually went with a run of 10,000 from Shenzhen Fulimei Technology Co. LTD. They turned out to be a great choice, I would highly recommend them for stuff like this. This isn't me shilling (I paid what they quoted), they just did an excellent job and put more attention than I would have expected for a relatively small order like this.
Now, I probably don't need 10,000 of these for Jumperless, but most of the cost is tooling, so I decided to make a bunch and have them available for other people who were in the same (very specific) conundrum pretty much at cost (because if you are someone having this problem, I can safely assume you're doing something cool and are therefore an honorary homie, so I'm going to do my best to hook it up.)
It was super scary putting in an order for 10,000 of something without a sample, but I was in a hurry and tend to be overconfident (it would be called hubris if I wasn't also generally lucky.) But yeah, they work great, meaning the LEDs fit with good clearance and things plug in with the same smoothness you'd expect from a regular breadboard.
If you don't want to bother making your own PCB for a RGB-lit breadboard, I've also made Jumperlux, which is an optionally RGB-lit breadboard, a solderable protoboard, and a bunch of SMD breakout boards all connected together in one PCB. It can be snapped apart to use any subset of those things as well. Or use it as a passive expansion board that goes next to your Jumperless and still shows the connections with the LEDs, there are matching LED data in/out pads for that.
I also had the plastic shells made in various materials and forms from JLCPCB's 3D printing service (once again, never been sponsored by JLC, but their quality/price/consolidation is so good that I'd rather pay full price from them over accepting a sponsorship from someone else.) You can either buy these shells on my Tindie store here or print your own with the files either here or at the Github link on this page.