Displaying bmp - 8bits\pixel

Hello, We have a black&white bmp with 8 bits\pixel. We succeeded in displaying it using glDrawPixels or glLoadTexture. But how can we display the image with different color palettes ? The classic color palettes are not supported by new graphic adaptors. In the old method, we had an array with 256 entries. Each entry was a gray scale. We could display the image with several color palettes. Can someone help ? Thanks, Zvika Vered.