Black and white display on my TV...Help please!

[amol0010]

I got aN american Dreamcast from my brother living in the US. I live in India, where the Pal system is adapted. I also have a very old TV with only a RF In system. It doesnt have the AV in system. When i connected the AV to RF adapter i get black and white display on my TV. How do i make it on color? There is also no chance to get a new TV. I also got a VGA adapter but my monitor is so small... 14" . Someone please help!!