Just going by other pictures I've seen of WW and comparing to yours.... I'd say you still have another 2-3 weeks at least (if your pictures represent the true colors... sometimes the camera washes out color). Of course I could very well be wrong..... let's see what the more experienced folks here have to say
In Holland we wait till 80% of the tricomes become brown/red,
however if you have more then a few plants, you may want to experiment, they say if you cut the plant while most of the tricomes are white you will experience more of a high thc buzz, and if you wait for the 80% mark, you the get the heavier couch rendering thc buzz...
im no expert tho, i just work in NL.