Looks like a fairly fast plant, but i think you'll need more than 3 more weeks, but is possible. You'd want to see some calyxes visibly plumping by now if you think it's going to be a 50-55 day length. Should be very well formed buds before day 40-42 to have a chance.
if you have too much wind directly hitting the colas, that might be why some have turned color already. could be minor wind burn.. could just be a fast developing flower... could be pollination.
if you don't find any sacs or nanners, easy to eliminate pollination as cause.
How is the stretch? has it abated? How quickly you start to see the calyxes plump and how quickly remaining vege growth ends are good ways to guesstimate total flower time needed. Stretch done and bud sites full formed by 30 days usually means 55-60 day plants in my experience. Should see plump buds by day 40-42. YMMV and each plant can do surprise you. Don't try to set a time to it. Let the plant tell you. Think bottom-up, not top-down -- react to cause and effect, not inductive guessing.
A diary isn't necessary, but if asking about ripeness and flower time, get some close ups of the buds. make sure ther's enough info to use.