[Why won't my color changing shoes work anymore?]

Hello.  I've been away from SL for a little while and when trying on outfits I discovered that the majority of my color changing heels no longer change colors.  Only the platform and the heels of the shoes will change but the straps and accessories will not.  Please advise on how I can avoid buying lots and lots of new heels.  I appreciate any responses to this question.

 

Thanks,

Pleasure