Because I do (the Real Reason is that it is supposed to be like that, the red in redpower is red, because that is redpower's collor; the build in buildcraft is orange with a line because, orange is buildcraft's collor and that looks more buildy and structurey; the rail in railcraft is crossed out and underlined to be like a rail line, the forest in forestry is green because forests are green; the thermal in thermal expansions is red and blue because thermal expansion dealed with lava and water, hot and cold; and the rock combines them all.)