Highlighting - Have color choices changed shades over releases?

I have some older styles that don't seem to match the currently available colors when I open them to edit.  In particular, the yellows seem muddier looking than in the past.  I can start to create a style, choose a natural highlighter background and get a nice, bright yellow.  When I open the color choice dropdown, that color is not there and the ones that are seem drab in comparison.  Is this a known issue?  It's not a monitor issue since my old styles are still bright.  I couldn't find anything on it but it's hard to pin down exactly what another poster would have called this so I could search out the issue.

Kaye