I think it is:
After the war, 2 men gave me life,
It was founded in Sept. 1998, by two men (Larry Page and Sergey Brin). According to wikipedia the only war that ended in 1998 was a War in Abkhazia, it's a bit obscure, but let's go with that!
In peace not in strife
They are a peaceful company, with a peaceful "do no evil" policy.
Now 17 years have passed, and my enemies I have surpassed
At time of posting, they are 17 years old (and 4 months).
For I am all around them
Google is everywhere, in lots of areas, and dominant in its core industry.
4 colors I flash, and 6 letters I splash
Logo has 4 colours, "Google" has 6 letters.
Across a great white canvas
Their home page has always been intentionally left mostly blank white.