You don't say what phone this is, or what update, or whether you are using a stock launcher or a third-party one (if you don't know it's stock, i.e. manufacturer's app). As the launcher draws the desktop this might be important.
If your launcher supports icon packs, try going into those settings and changing them (even just changing then setting them back to what they are now).
The funny thing here is that it looks like just Google apps are affected, but this doesn't look like a Google phone (and Google haven't adopted that icon style - I'm using a Pixel, so can say this for sure). But it's kinda odd for a manufacturer to apply an icon theme just to Google apps and not even their own?