Handling different tint for different sources

[lnx64]

I couldn't think of the actual subforum for this.

Apparently I have some seriously crappy sources. My Roku, Sega Genesis, and DTA all require drastically different tint settings on my TV, just to be correct. Luckily on all of them, I can pull up the SMPTE patterns (even on the Sega with a special test cart).

Let's see.

Sega: -19
DTA: +4
Roku: +13

I have never seen equipment so out of whack like this, but the TV's I have, are either the knob types, or the OSD menu types that sadly only treat the tint setting globally and not per input.

Is there any possible way to shift the hue with a circuit I can construct from the composite video signal, to add some form of correction? It's getting so old changing the tint settings just when I decide to watch something different.

It's a minor nitpick, I know, but damn, I've never seen such drastic differences in the sources like that..

Sad thing is, I think the only one that's actually accurate, is the Sega Genesis, ironically. It matches perfectly with my Sencore generator. (I know the Sega internally is RGB and is converted to NTSC, and the DTA and Roku's are both internally Y/Cr/Cb and converted to NTSC--maybe that's why?)