The Motorola boxes are notoriously bad at HDMI -- check the Wikipedia article on them for software/firmware version specific stuff.
Video which shows and image but is tinted "shocking pink" or "ghastly green" usually means the connection got established with a mismatch in "data format". The digital video is being sent as RGB when the TV wants YCbCr or vice versa. Usually this is negotiated automatically when the connection is set up, but sometimes you have to force it. See if your TV has a setting for this on its HDMI input (odds are it will not). YCbCr is the normal setting for HDMI TVs. RGB is the normal setting for DVI TVs.
The Motorola HDMI boxes all have the extra HDMI settings above a certain firmware level (check the Wikipedia article), but if the box gets confused enough to think the HDMI connection is not live it won't display them. If you've got really old firmware on your box, try swapping out for a different box.
Unplug the Motorola box and your TV. Get a fresh, well made HDMI cable. Keep it as short as will work (under 10 foot long is best). The Motorola boxes have really lousy HDMI output circuits and you want to do everything you can to minimize reduction of the signal due to the HDMI cable itself. BEFORE plugging it in, use a flashlight and check the HDMI sockets on the Motorola box and on your TV looking for pin damage. If all OK, plug in the cable, turn on your TV. Give it 30 seconds or so to get set and then plug in the cable box.
When the cable box has woken up, hit the power button on the cable remote to turn it off (actually to put it in "standby") and then hit the menu button on the cable remote to go into the special menus. The line for additional HDMI settings should be there below the resolution settings. Set the video resolution first, and then scroll down to that and hit the right arrow to go the extra page of HDMI settings.