The translucent dome on one of my Hue Outdoor Motion Sensors perished after 6 years out in full sun here in the Cote d’Azur.
I really wasn’t up to paying >€45 for a replacement plus the hassle of re-integrating it into my various automations so I looked around for a replacement. Nothing on Hue, Amazon or eBay (not even a cheap damaged one). I fixed it by using the standard lens on an LED light bulb, cutting it off at the right diameter, sanding the rough edge, popping it up and holding it on with a dab of glue. Works a treat.