Organic cotton jeans used to feel like a penance you paid for having a conscience, stiff as cardboard and the colour of weak tea, and you wore them because you should rather than because you wanted to. That has changed properly in the last few years. The better mills have worked out how to spin organic cotton so it actually moves, takes dye evenly and doesn't feel like you're breaking in a new pair of oven gloves every time you sit down.
Before you buy, check the weight, because organic cotton denim varies hugely and a lighter weight will crease and go baggy at the knee far quicker than a heavier one. Look at the stretch content too, most organic cotton jeans are blended with a small percentage of elastane for recovery, and if there's none at all they will hold their shape less well through a day of sitting at a desk. Check the rise and the pocket depth while you're there, and have a feel of the inside seams, because cheaper organic lines sometimes skip the proper flat felled seam and you'll feel it rubbing by week three. On the clashing side, keep them away from very shiny synthetic tops and jackets, the matte, slightly textured finish on organic cotton sits badly next to anything with a sheen, it looks like two different decades arguing. A stiff structured blazer fights the softer drape too, a looser knit or an unstructured jacket suits it better.
For colour, mid blue washes and a proper washed black are the easiest to live with, they fade gently rather than going patchy or grey, which is what raw indigo does if you treat it kindly and wash it rarely. Very pale bleached washes show wear unevenly on organic cotton, the fibre isn't as uniform as conventional cotton and that shows up fastest where the dye is lightest. Over months, organic cotton denim softens properly rather than just going thin, and the fading at the knees and pocket edges looks like it happened to the jeans rather than at them, which is the whole appeal. Wash them cold, inside out, as little as you can manage, and skip the tumble dryer, because without a resin finish they shrink more than you'd expect, and once that's happened it isn't coming back.
What they won't do is hold a very fitted skinny shape all day without bagging at the knee, no matter how careful the blend. If you need that kind of recovery, this isn't where you'll find it.