@Gerbrand333
Colours:
While using the website (only on the website) you can personalize the colours of different overlays in settings. (Customize color scale)
Weather Picker:
On the website, you can just click and hold on the weather picker and move it wherever you like and it'll update the info as you move it.
On the app you just move the map "under" the weather picker and it updates as you move the map.
Hope that helps!