This is a Sunday brunch with the guys or family outfit! I feel like you don't have to wear dress pant to wear a blazer with a dress shirt. Just throw on some plain, simple jeans and add on that beige blazer with a neutral color dress shirt.
Now here is some really beautiful creativity in menswear. I love the way the blue and white stripe shirt bring out the pattern in the blazer, and the browns will not overpower the outfit, since the pants are much lighter.