CSS validator report has changed

Two days ago I tested a HTML page with the CSS validator and it passed with
no errors. Today after making some slight amendments tested the same page
and received 300 warnings regarding, mainly, colours. Many of the warnings
were similar to -
 
Line : 39 (Level : 1) Same colors for color and background-color in two
contexts .legalbar and .faqsubheader
 
as the two classes have no relation to each other and can't be used on the
same item what is the point of the warning. Surely it is allowable to have
the same foreground colour in one circumstance as a background colour in
another circumstance.
 
Has your validator analysed this correctly, if so, what is the purpose of
pointing this out, especially as 2 days ago it did not.
 
Graham Williams