Colour t-cut shouldn't change the colour of the car: does pink polish turn it pink, or normal brown t-cut change it ? No t-cut or colour-polish is ever the right shade for the car anyway.

All it will do is lift off any in-grained dirt & make it shinier & cleaner looking. Go for it.

If you are that bothered about it possibly changing the colour, do a test on the slam panel, or inside the boot first to check.