I pulled a pic from YouTube. His meter is white and his tick mark is that darker area I believe. I do my meter in black so I think my tick mark shows up in white as some sort of contrast.
Run the video at 0.25 speed and in HD starting at 1:53 and you should see what I'm talking about. The meter isn't
fully green, it's got extra at the end, like 1mm or so at the leading edge of the meter. You don't see it while it's moving so you end up releasing later than you should, but when you get a green release then you see the mark appear.
Edit: It's easier to understand the earlier release point if you practice during the free throw drill since you have more time to watch the meter. Once you get it a few times then I think you'll understand what I'm trying to explain.
Edit 2: Picture from mine. The white portion is clearer in mine.