I have some problems with the hill colours in Days of the fox. Looking to 20A the hills inside are clearly darker and therefore level2.

But what with the single hill on 13b and 14b?

Same problem with the overlay tiles, the doubble hill and the single hill have different brown tones, but what is level 1 and 2?

For convienience I usualy rule that all the single overlays are Level 1.