Dwarf Gourami, Dark colour, Please help!

[Mumble]

I have two dwarf gourami's in my 26 gallon and both of them are not eating and the one has developed a dark discolouration mostly on his head. I have been battling a high pH (8.6) but from what I am told they will tolerate a higher pH. Nitrite and Nitrate are fine. Any ideas what it could be? Thanks.

 

[kellyinvancouver]

Is it by any chance a vertical, bluish curving stripe? My dg's head turns a brilliant blue whenever he is.... "in the mood" :|