I'm blond too, and my facial hair is very pale and Spencer-ish... and being in my 40s, it's also going grey. I keep it to about a centimetre in length. It does help with my passing, and I think it's
gorgeous. There's nothing wrong with having blond facial hair. We're so used to seeing dark beards on men that we tend to think that this is some sort of virile masculine ideal that should be attained. But that's just nonsense, and there's nothing wrong with being pale & interesting.
That having been said, the problem with naturally blond bodily & facial hair is that it is probably very similar in tone to your skin colour, and the lack of contrast between the two makes it difficult to see. Which brings me to the 'plus' side of having blond facial hair: the ol' five o'clock shadow isn't as much of a worry for us!

So the only ways to make it visible are a) grow it long and perhaps rock a Viking number, or b) change its colour.
(By the way, guys: 'blonde' and 'blond' are amongst the few gendered words in English. Blonde=female and blond=male.

).