I think I can see where you mean. It is in the sideboxes that you are looking at?
You need to edit your stylesheet.css file. This should be in includes / templates / YOUR TEMPLATE / css. If is is not it means that you do not have an override style so you need to look in includes / templates / default_template / css / . (But if that is the case I really recommend that you explore overrides. They are really a must )
Someone has worked on your stylesheet.css It is very hard to read. :wink:
You need to find the bit that reads :
h3.leftBoxHeading, h3.leftBoxHeading a,h3.rightBoxHeading, h3.rightBoxHeading a { font-size: 1em; color: #FF9999; }
and edit it. The #FF9999 represents a colour. Just change it to another colour. It is in RGB format so if that confuses you then do an on-line search for RGB color picker and things will become easier.
If I have misunderstood where the problem lies then forgive me. Purple is often a color for a visited link so that might be the issue. If it is I can show you how to change it if you are very detailed about where the problem is occurring.
Nik