[phenixbb] coot and mtz interpretation

I'm having an issue that when I launch coot from the phenix refine gui it loads the pdb and mtz fine, but the FoFc map colors are green and royal blue. When I open coot first and then load the pdb and mtz files, the FoFc map colors are green and red, but the blobs that were green in the phenix loaded maps are now red and what was royal blue is now green. Has anyone else had this issue? I am running a mac with OS X 10.6.8 and coot 0.6.1 and phenix 1.8.2-1309. I have an identical mac running all the same versions and everything loads green and red as expected. Is there a parameter file somewhere that tells coot how to display the phenix maps that may provide a clue as to what is going on? I appreciate any suggestions, Heather