Squirrel
Colours
Hundreds of years ago, colour variation was used to identify 60+ subspecies of Eurasian Red squirrel, but more scientific research whittled that number down to 23. The varied colour squirrels you see here are all from a single area of one park in Sweden's 2nd biggest city. Ranging from pale red (rare) to dark red (common). This Vulgaris subspecies (meaning common) is the only one you'll find here in Scandinavia (and western Russia too), but their colours can vary massively.
Their winter coat makes judging their original colour more difficult because the thicker coat tends to go rather silvery grey. They have it for most of the year and it can cover up most of their natural colours. Their ears, legs and tail usually retain their main colour that you will see in the summer, even though they do eventually lose the ear tufts as well.
Leucism
One interesting colour characteristic that we found in Switzerand was a slight leucistic tendency. Some of the darker squirrels had white paws. We saw one with both front paws in white, but it ran away too quickly for me to get any photos. One image I found online from the area showed a dark squirrel with all four feet in white. I found one other with only one white paw, which was fortunately a bit more photogenic. This condition is not to be confused with Albinism, which affects the whole body and also turns the eyes red.
Subspecies
Squirrels in Switzerland are the central European subspecies, 'Sciurus Vulgaris Fuscoater'. This doesn't have an effect on the look of the squirrels however. The darker fur on some of the Arosa squirrels is likely due to different habitats at higher altitudes (Swedish pine is red at the top, where their nests are). As you can see there were still squirrels with bright red coats here and they become the more popular ones at lower altitudes, so it's likely there is little to no genetic difference between them.