Some people see green (laser or dot in an optic) better than red. Others see red better. I bought red/amber for years but realized a couple years ago green works better for my eyes.
The holster I'm using it the same one I used for the older 1.0 Shield. I modified it to fit the Shield with the light/laser combo on it. When I got the light (TLR6) for the Shield Plus I tried it in that same DeSantis holster and felt it fit good enough to worth ordering another DeSantis to modify so I could have an IWB holster in both grab bags.
Hopefully others will chime in with the brand/name of the holsters they use. Or you can search on the forum to see who uses what. Lots of threads on the Shield Plus pistols and recommendations for lights, holsters, etc.
The DeSantis I use doesn't have a positive lock of the pistol into the holster but it's an IWB holster and it shoves the back of the frame up into the area below my ribs so the pistol isn't going anywhere unless I grab it and drag it out of the holster.
After carrying a P07 for years you wouldn't believe how many times I'd be walking across a parking lot or in a store and suddenly get the notion that I'd somehow, somewhere lost my Shield out of the holster. Then I sort of rub my elbow across it as I walked and realize I still had the Shield, it was just not "showing up" in my mind because I couldn't feel it at all.