Most TVs of the last 5-10 years have a RGB-capable Port, but usually just 1 of them.
Some descriptions on the net are however incomplete, you need apart from 2xAudio and 3xVideo a few other connections - one is sync, one is a "RGB-Switch" which needs to be some odd Voltage like 2V and I think there was another one I forgot.
PS. I think the Amiga-Port has a Pin called composite, I kinda expected the Cable I built to run with non-RGB Scart too, but it doesnt?
Oh and RGB Picture Quality is kinda like 3 times better
Edit:
Theres the Scart Pinout
Pin 8 should go to 12V
Pin 16 should go to 1-3V (connect through a Resistor around 700 - 800Ohm to 12V )