In your downloaded files, the C3 and C4 both have "Red-with brackets", whereas in the original RSS files, C4 is red and C3 is yellow, according to the website you linked. Also, the C5 in the original RSS is "Red-without brackets" as shown on the website, but the C5 in your files has the "Purple" one, which is the old Ultrasofts colour I think. Is there a way to have the same design as on the website; if it's not possible no worries I guess we'll have to live with it.
Edit: After having read up a bit more, I have realised that Pirelli will nominate 3 compunds to use for dry race at each track, and those colours will be white, yellow and red, in order of hardest to softest. The images in the website you linked pertain more to testing I believe. The Purple colour also seems to be not in use anymore.