That is not a good cut suit for him. No one wears 4 button suits anymore. That one looks like a 5 buton suit to me.
I actually like the colors, but not on him, and definitely not in the middle of winter. Thats a spring color suit.
But what are you going to do, it's not like Dexter is well versed in haberdashery.
He gets an A for effort though.