[simply Nathan]

One version of dwarves I had were born fully literate and had to learn speech just like everyone else - which often took longer, due to having a good medium of communication already. All the other races in that setting start using the dwarvish alphabet to write if the interact with them enough since that's easier on everyone, even if they're writing words that look like gibberish to a dwarf who hasn't learned to speak multiple languages yet.

A recurring trend in my dwarves is either to have white beards and black skin or black beards and white skin. Rarely albinos because who needs skin pigments when you spend your whole life underground anyway?

Dwarves with common human skin and hair colors (browns) are dwarves that are at least part human in their recent ancestry - thus, it is half-dwarves that adventurers most commonly are and interact with. Pure dwarves are shorter (3' instead of 4-5') and stronger (ST 14-20 instead of ST 10 + Lifting ST 2) but also liable to turn to stone in the sunlight - you don't know if you have the condition until you've been exposed to the sun so why try? And this is a world with two suns so the day is twice as long as the night.