You seem to misunderstand my intent. I am trying to help you in several ways. However there are issues at several levels here and you may not be connecting the help I'm trying to give with the appropriate issue.

Re: Hashes, Arrays, Comparing Values to Elements was an attempt to address your understanding of hashes and also to suggest a way of presenting questions at PerlMonks that will help both you and us understand and reproduce the important aspects of your problem. The code I offered was not a direct attempt to solve your css generation problem.

Re^3: Hashes, Arrays, Comparing Values to Elements tried to explain what an XY question is and to suggest that you have a higher level issue (the perceived speed problem) that really ought be addressed at a much higher level than the hash oriented question. I suspect that "making the script faster" may not be the real issue at all, but you need to tell us what the bigger picture is for that to be clear.