I guess depending on size and colour rendition of displays it can be easier / harder, but overall I’d still say it’s a poor choice.

A choice of different colours is OK, but specifically those 2 are pretty hard to distinguish. Simply changing one of them to black, which looks like no other colour used in the map, would be much better.

I don’t think a gradient works for colouring a map like this: we can distinguish gradient colours when they are next to each other, but if 2 countries far away have adjacent values the colours would probably be too similar to tell the difference.

Poor choice of colours: distinguishing between the orange of 2025 and the red of 2040 is very hard, especially considering most people will read this on a small phone screen.

According to that map Mexico is 2040, not 2025. The choice of colours is terrible.

I’m going to paste here the comment I wrote on another post about this same issue:

Organic Maps and OsmAnd are not adding ads during navigation. Nor “promoted pins”. Nor ads when browsing the map. Nor tracking your every move.

Seriously, give them a try. And remember that, if the maps are lacking information, you are free (and encouraged) to improve them on OpenStreetMap.

May I recommend OSS Document Scanner + Syncthing? Both apps are FOSS and it looks to me like that they might be able to replace what Microsoft Lens does for you with the advantage that you are free of Microsoft software.