Fill colour defaults back to the stroke.
i have finished outline new design , went start colouring blob brush. after 1 pass brush colour went the fill stroke colour. means not have object bunch of scraggly lines intersecting. i pulled previous image worked fine yesterday same thing. using ai 2017 version. new bug ? double click blob brush , set settings need them. read settings here: how paint fills , strokes in illustrator and watch video here gs-06: using blob brush , eraser if doesn't help, please post screenshot of problem. More discussions in Illustrator adobe