Could add any women's sports as long as you at least balance the number of scholarships. CU already falls quite short of a 50/50 split that reflects its student population, which means CU doesn't meet Title IX goals. (It's hard to get there with football having 85 men's scholarships.). CU might be willing to add sports so that it's an equal number of new women's scholarships to men's, but there's no way that CU would add a men's sport without at least adding equal scholarships on the women's side.
As an aside,
Title IX is what killed college wrestling. There isn't a women's equivalent to match up with it.
Here's the list of scholarships per NCAA sport:
http://www.scholarshipstats.com/ncaalimits.html
fwiw, the combo I like based on Colorado culture and what I think CU could be really good at while not having major start up costs is:
Men's: Lacrosse (12.6 scholarships)
Women's: Beach Volleyball (6 scholarships), Triathlon (6.5 scholarships)
I also think that MLAX & WBV would draw spectators and interest for spring sports at CU. Tri is in the fall and I like it mostly because it's such a perfect cultural fit and also because ASU was able to start a program and win consecutive national championships -- I believe that CU could overtake them.