I've made BHO 3 times and everytime its worked but come out black. it starts out yellow and then as i evaporate the butane it becomes black. i use a galavanized steel pipe for extraction and i know you're not supposed to do this b/c the butane will strip off the inside of the pipe, but is this why its coming out black or is it due to something else? it cant be due to the type of butane because i used colibri once and it came out black. after that i just used the cheaper brands.

Yeh It's probably the metal pipe that your using, try using a proper honey bee extractor, or try the coffee pot method and see if the resulting oil is of a different colour then.

H.T.