There's a firmware issue on current versions of firmware for Linux. The fix will end up in up in a 3.3 Kernel. Take a good read of <http://www.mythtv.org/wiki/Index.php/Hauppauge_HD-PVR>.
Note this part in particular:
Note: 29-Aug-2011: The latest version of the firmware, 1.6.29207, dated July 27, 2011, causes oversaturation and color issues with the encoding of the analog signal. Until this is resolved, you do not want to upgrade to this version. Version 1.5.7, from June 17, 2010 appears to work. Hauppauge has acknowledged the issue and provided a link to the earlier firmware for non-Windows systems on their support page: Hauppauge HD-PVR support
A patch has been submitted upstream to fix this issue and it has been merged into Linux kernel v3.3-rc5.
This appears to be the fix:
Until a patch that sets the new defaults is committed to the kernel, you can use v4l2-ctl --set-ctrl brightness=0x80 --set-ctrl contrast=0x40 --set-ctrl hue=0xf --set-ctrl saturation=0x40 --set-ctrl sharpness=0x80 to set the proper defaults.
You might be able to put that into a channel change script.
Hope that helps!