I've been a user of Piriform's software from a long time ago. These guys are making a great job with their free software. 
Well, I'm writing here, cause I found some issues with the interface of CCleaner, on Windows XP (SP3, don't know if on SP2 the same happens).
As you can see on the screenshot shown bellow, the blue lines shown as a square isn't the "true" blue that some of the older versions had. This happens on the "Cleaner" panel, "Tools" panel, and "Options" panel. The "Registry" panel doesn't have this issue.
Hex codes included in the screenshot.
Greetings!