I'm encountering the white text, blank background Send Button problem too. In reading the FAQ.pdf, I thought I could solve the problem by editing the uddeim css file. I tried that and no matter what color I changed it to, it appeared to be ignored.
I then tried changing Community Builder templates after reading a this thread. I tried them all and they would change the template, but the text remained white and the background of the button stayed transparent.
I'm using a template system that includes 7 variations. All seven template options for Joomla have the same problem within Community Builder when I get to the Private Message Send Button section. On three of the template style choices I am using, I can read the "Send" button, but only because it is white text on a darker background. On the other four it is not readable. On all of them the button itself is transparent and the text is white.
I'm now believing I have a CSS file or some plugin that is overiding what I change in the uddeim css. I need a little more assistance in trying to figure out what text I should be searching for to try and correct the problem. I'm not all that skilled with CSS or anything, so I need to know where to look a bit more than searching for the color white in all the css files (that would be fruitless for me).
Let me start by first saying, "Thank you!" The speed of the response and a code-level response at that is greatly appreciated. Let me know where you'd like me to post some positive feedback and I'll be happy to do so
Now, having said that... let me just state that I feel like a bit of an idiot right now. I became a victim of tunnel vision as I searched for possible solutions. I was trying to follow directions a bit too much instead of opening my own eyes. Right there in front of me was not just uddeim.css, but also uddeim-ie.css.
The whole time I was just needing to edit the IE version to get the solution I was seeking. I changed the background color there to "blue" as suggested, and had my fix.
I am loving the work that has been done with uddeim and am obviously impressed with the rapid support response. Thanks again!