Look deep into the history and philosophy of the Gurus. As for if it's okay to be a white sikh, of course. I've been surprised many, many times as I've seen 'white' (put in quotes because race doesn't really matter, just saying to show a point) sikhs are better than some sikhs who are actually born into the religion. I've met an ex army priest who became a Sikh before and a few others who weren't born into Sikhi. Here's a video of some (you can just google/youtube white sikhs)