If your wardrobe is all sorts of different contrasting color schemes, the blue may make it more schizophrenic if it doesn't match anything... that's a good or bad thing depending on the look you're going for and how much attention you want to grab... the brown is more neutral I think, but also good if you wear "harder" clothes, like jeans, clothes with sharp clean lines, etc... it will look "sharp"... these are fairly over the top for brown though?
If you like lots of muted tones or toned down patterns, go with the blue. You will stand out and feel fresh.
The branding is also toned down quite a bit on the blue, whereas the brown it looks like a cow brand... the blue is also more of a statement piece on it's own... so if you plan to go naked to meet your date, you will look great in the blue
.. but the brown might make you feel like a bit like a 70's porn star...especially if you have a 'stash...\
I can't choose for you. It depends on your look and what you're going for.