Modding a camera by replacing the UV/IR filter makes the camera much more sensitive to the red and IR - so the images come out pink. There may also be a haze caused by the extended UV sensitivity, so you may also need a UV and long-wave IR blocking filter.
As someone else wrote, for astro, you need to do a colour balance, both with the camera and with software. For normal photography, you also need a UV/IR blocking filter over the lens or behind the lens as well to get the correct colour.
Have a look at
http://www.iceinspace.com.au/forum/s...UV%2FIR+filter for some examples of photos with and without various filters and white balance settings.