Shirtless,

Go with your gut. While your original intentions were to wear a blue shirt, the fact that the black one stood out means that’s where your preferences for the day are leaning. Trust yourself; if you don’t, no one else will.

And if you’re still unsure, flip a coin. If it lands on blue and you’re happy with the results, go for it. If it lands on blue and you’re still unsure, wear black.

Just my $0.02
Julius Pleasar