Perfect fit in a men's medium for my 5'10" 150lb son.  I was expecting a slim fit and it is.  If you have heavy legs, lots of muscle i would size up or look for a baggier adidas pant.  Even on my son who is definitely on the slim side the fabric is more clingy at the calves especially.  I am not saying don't buy them - they are great.  Just that they are more like performance pants.  The upside is they don't swish or touch when you are walking.  FYI the color is spot on the image portrayed.  It's a bright cherry red!