The glBitmap COMMAND

glBitmap( width, ht, x_0, y_0, x_mov, y_mov, raster);

where raster is a pointer to a bitmap.
-- See [Guide, Ch.2] for how to create a bitmap.

This will draw the bitmap using the current color has been initialized. So you may want to first do

glColor3f( R, G, B);

The origin of the will be placed at the pixel position

CURRENT_RASTER_POS + (x_0,y_0)

-- NOTHING HAPPENS IF CURRENT RASTER POSITION IS INVALID.

Then for each pixel where the bitmap is a 0, we do nothing.
-- For each pixel with a 1, we color that pixel with the current color (or generates a fragment with the current color).

Finally, the current raster position will be updated to

CURRENT_RASTER_POS + (x_mov,y_mov)