Unfortunately, while Cultra is overall a fascinating place, superbly presented, just about anything they have painted themselves is wrong, sometimes totally.
800: wrong crest and tender lettering.
C & L loco: green probably too light.
C & L coach: lettering completely wrong in style and colour; maroon probably a bit too light.
Castlederg carriage: Lettering completely wrong. Original shade of maroon hasn't survived to my knowledge, so I can't comment on its accuracy.
Donegal open wagon: bodywork in original unrepainted Donegal grey, but metal strapping shouldn't be black.
GSWR covered steel van: completely wrong. Body paint, chassis paint and lettering, the lot. In GSWR days, the whole thing was plain black, body and all. Lettering wrong style and shape; should be smaller. In GSR and CIE days, plain darkish grey with "G S" or (later) "flying snail".
Drew's models are truly superb. I like the CIE livery on them personally, I think it looks very well. It would have been amazing if CIE had painted all their locos that way instead of plain grey, though I have to say I think that the grey sufficiently unusual to have its place too. How've for young modellers it's important, from the historical perspective, just to point out that in fact few CIE locos ever wore green, and those that did belonged only to a few classes. The mighty J15s, for example, by a huge stretch the most numerous steam engines ever to run in Ireland, were be anything but grey after about 1915.
The RPSI's 461 was painted green to show lined green CIE livery as elsewhere if only survived on "Maedb" in Cultra. However, prototypical paints are notorious for not transforming well to models, as many of us know, and it's worse in reverse. Thus, having copied CIE green from Drew's models, 461 has end up in real life in the wrong shade. Modellers will be award that to copy CIE green, a visit to Cultra or Headhunters barber & railway museum in Enniskillen is the only show in town. Enniskillen has a genuine flying snail mounted on a board painted in Inchicore.
Other stuff was painted before it came to Cultra, so it's ok!