Original review 3/31/18 - I read a ton of reviews before ordering these and seems like there are a lot of contradictions - folks who say it was too small and others who found the waist band slips. Here's my experience. I wear an M/L, and ordered an S. It's a perfect snug fit right out of the bag - comfortable when I sit, but isn't going to slip down. I haven't worn it yet for a whole day, so I can't say if it will stretch out. Which size you buy will depend on two things - how you want it to fit and your body shape. If you're looking for typical loose linen pants, I'd keep away from this one and look for one with an actual closure (buttons or drawstring). The waist band on these is a stretchy piece of jersey fabric - it will only hold up if stretched enough. Secondly, if you have heavy hips and thighs, these are not ideal. The width of the pants at the hips/top of the thighs is pretty average but the waist band is larger than average. It will work a lot better for straighter figures or like me, if you have wide but high hips. This allows the waist band to stretch more and hold in place better. For reference, my hips measure 40" and the S fits.
Color - I bought white and while it is very slightly see-through, it's not bad at all. Wear nude thongs or boyshorts and you'll be fine. I have tan skin and you can't really tell.
Finally, the length - the S size is exactly 32" inseam. I'm 5'5" and have 31-32 inseam, and these are great.
Update 6/1/18 - I've had the chance to wear this a few times now, including for a whole day. The reviewers who mentioned stretching are right - it stretches a LOT after a few hours of wear, sitting, standing etc. Both the stretchy waist as well as the linen part loosened up. I found I could no longer keep the pants up without constant tugging, so I wore a white belt at the hip. It's not ideal since there are no belt loops, but it does work for a while. It's better suited for a couple of hours, not a full day of wear. Docking another star for the stretch issues.