For sky replacement, please put a red border (or any bright colour) around "the last sky used" . The last sky used is hard to spot among hundreds of skies when the thumbnail itself is mostly blue.

I edit real estate photos and replace ugly grey New Zealand skies all the time. I have a library of about 500 skies that I’ve uploaded to Adobe. When I hit F7 the default is always the top sky in my box. I scroll down till I find a suitable one (e.g. sky 365). But when it’s not looking good and I want to choose another sky, I don’t want to scroll from the top sky again, rather carry on from sky 365. This is wasting a lot of time. Simply changing the colour around the last sky selected from blue to something bright, like red, will go a long way.