Agreed - it was painful but worth the time to change background to teal w/ StyleBot Chrome extension. Really like how this is all laid out and the term sheet is right there at the bottom.
The darker red is definitely better, but generally red is a bad color to use excessively. Plenty of studies have shown that red can invoke the fight or flight response and increase stress.
Even the new red is painful on my eyes. I navigated away before I finished reading, and when coming back here, it still created an afterimage on my retina.
I recommend a much more muted background, especially for the textual portion of the site. Run red banners down the side if you must, but change the text section to a more readable contrast.
More of a neutral background would be a good start, something like the Kima Ventures site where white-on-red is used as a bold title versus the whole page text.
Don't have the whole page one background color - use it as either side panels as suggested below, or as a focal element like this: http://imgur.com/hwsUhKI