Hi...

My TV does not seem to be able to split the Y and C signals from the
composite input pin on the SCART connector. I get a black&white picture.

What is the signal source that comes out in B&W?

However, my VCR does output a proper, colour picture to the set. I'm
guessing that the VCR outputs RGB signals, and the TV is using those.

Are you also using the SCART input at this point?

IMHO if it's a DVD player giving you black and white, I'd be 99% sure it's
outputting the wrong standard eg NTSC, PAL-60 or whatever, and your set is
expecting something different (eg PAL-50).

Go thru the device setup menus and change the output type to match the TV.

Craig