Alphabetizing Splitting by Category // And Question about Text Color

My Display Post grid is supposed to include two categories of posts.
I also want it to display all matching posts alphabetically by title – regardless of which of the two categories it comes from. My code is successfully pulling both categories in, but its alphabetizing all of Category 1 then started over with alphabetizing Category 2. Any help?

[display-posts posts_per_page=”50″ category=”category-1, category-2″ order=”ASC” orderby=”title”]

One other question: Is there anyway to get it to color code the displayed text (post title) based upon the category it came from? Like Category 1’s text is blue and Category 2’s text is red? I can’t find anything like that in the guide.

Thanks!