Am also down to just these two and black is right. Can't see any recognisable phrases -- black mother? bother black? black river?
Gtfl further ideas. Tks.
I thought I was on to a winner with 'board' as the theme word but I can only get it to work with Duckboard, Motherboard, Skateboard, Tailboard, Scoreboard and possibly Riverboard.
The instructions say one answer has to be shaded which "could be a clue to the missing theme word" (sorry this wasn't mentioned before). One clue answer is ARMBAND which I think must be that clue and indicates BLACK.
My latest theory is that there is a typo - the O in ?O?H?R comes from the fifth letter in boudoir, now if this was mistakenly taken as boudIor, making it ?I?H?R the answer could be FISHER which Chambers gives as going with black. But that is the last I'm going to think about it.
It really is a tough challenge isn't it? One of the clued answers is TERRAIN so I wondered if LAND might fit : Landmarks, Motherland, Land Rover, Buckland, but it doesn't seem to work with B_R_Y or T_I_.
Hmmmmm, thinking caps on again.