My epson printer wont let me print it says buy new black ink when i am not printing in black but in colour?

All of the ink cartridges have to have ink in them. Trust me, even color prints have to use some black for gray tones and mixing colors. Ink jet printers require all the cartridges to have some ink in them.

Here's the answer: Go to http://www.inkproducts.com/ and buy a CISS for your printer. It will save you tons of money, you never change cartridges and never run out of ink [yes, you do have to fill the tanks once in a while] Bulk ink is cheap. The CISS will pay for itself in a month. Don't forget to get a Waste Ink Container, it hooks up to the printer and instead of the unusable ink going to the waste ink pad, it goes to the container which can then be emptied, washed and used over and over. The waste ink pad when full will need to be replaced or the printer will not print. Changing the pad is messy and a PITA.