Text color appears to give it blurry edges

I have to use a particular color of large text for some titles (client color), but I notice that in Preview mode it may look fine, but when I render the video, the character edges get blurry. I noticed that this seems to relate to the background color; that is, using a light gray background makes the text look fine. But a different color (client color) makes the text come out blurry, or have an apparent outline on the letters (without me selecting any stroke). 

Very strange, and I've tried a few things that do not help. 

I'd love to hear from someone who had similar issues and found a way to fix in Premiere. Again, it appears to relate to the video rendering, not just text against a certain color -- because graphics I import look good in themselves.... but not so good in a rendered video.