Can someone tell me what to use ..I need to make a cake with oriental theme using white, red & black buttercream
The best black and red coloring is by Americolor. I buy it a my local cake supply shop but you can also get it on line. Remember that the color darkens as it sits. I get amazing reds and black. Look at my photos and see the red on the valentine cookies and the black on the butterfly on the cookie bouquet. Once you use this stuf you will never use anything else.
When I make black icing, I usually start with a chocolate BC. It's much easier to get a dark black from a brown base than from a white base. It depends on whether or not you want a chocolate BC on the cake (some people don't).
When looking for a little black to pipe and not ice the whole cake I just add some hershey's special dark cocoa powder to my icing and get it good and dark. Then I add black color to finish it off. This seems to work well for me.