I did the same thing (not with this particular kind, but with sneakers from NB) and then I eventually went to try to buy an identical pair and it turned out they didn't make that particular model anymore. Which sucks, those were the best fitting shoes I ever owned.
And on topic I wouldn't change the lace color, I think they look good as-is.
I had a pair of new balance sneakers like that I literally ran into the ground the sole came off so I was forced to duct tape it back together.
I did the same thing (not with this particular kind, but with sneakers from NB) and then I eventually went to try to buy an identical pair and it turned out they didn't make that particular model anymore. Which sucks, those were the best fitting shoes I ever owned.
And on topic I wouldn't change the lace color, I think they look good as-is.