Do "русый" and "русский" have a common root?

Question

Does the name of the hair color русый come from the name of the people/land?

Answer 1

Русый originates from the Slavic word *рудсъ (red) and is directly related to words like рыжий, рдеть, рожа (disease) etc, and also to the words orginated from the same PIE root, including English red itself.

Most sources agree that русский and Русь originated from Rus, the name of the Viking tribe which settled on the east cost of Baltic sea.

The name of the tribe is thought by some (Vasmer and others) as originated from Germanic word meaning "to row" (as with a paddle). However, since the origin of the nation's name is a very politically sensitive subject, there are numerous theories which derive the word Русь from other words. Trubachyov derived it from an Iranian word meaning "light" (which originates from the same root as русый does), though agrees that it was the name of a Viking tribe too. If this point of view is true, then the two words are related but that would be a very remote relation.

Some derive the word Русь from the name of the river Ros (in what now is Ukraine). However, in Slavic it was read as *ръсь which would yield a fleeting vowel in the root (compare ръжь - рожь, ръжи - ржи) so linguists deny this version.

So answering your question: русый definitely does not come directly from русский or Русь, but the two may (or may not) have a common PIE ancestor meaning "bright color".

Answer 2

Yes, they both derive from name of ancient 'rus`' people