I am wondering the differences in smell between white, yellow and orange.

I have currently orange changa and it smells pretty musty like types of off food (not like plastic). The best smell I have found is bright light yellow goo on mullein (smells like some aroma from an asian temple) but it is hard to seperate it from the orange goo in pulls. I wish I could upload you these smells somehow!

Smell is just the nose receptors picking up molecules that are flying off substances and converting it into electric impulses.

My white fluffy stuff barely has a smell, but just enough that it's pleasant and I could sniff on it all day. The yellow has a slightly stronger smell similar to white fluffy, still a pleasant aroma. The orange stuff is definitely pungent with a plastic type smell to it.

When I made my changa using ethanol it had a slight musty smell towards the end of drying but I think it was due to the water in the ethanol taking longer to evap. Once it dried and cured it smells like a finely crafted bouquet.

Are you certain there's no moisture in it that could be causing the musty smell?

Thanks Spaced Out 2, my herbs are looking and feeling damp so that is most probably the culprit.

You hit the nail right on the head on the smell

I am going to acetone some peppermint leaf and cinnamen into it, maybe even some vanilla essence to mask all those plant impurities that is causing the stench which won't go away after fan treatment.

My Acacia extract on mullein smells like the most exquisite hyacinth growing in a beautiful grove of blooming cherries. Ah, the indole! Smells like tripping.