There are some variables involved like , what else is in your mix, how many worms did you start with. Your mix should start looking dark when near finished and will more resemble coffee grounds. Good luck with worming, patience is a virtue.

Like Steve said there are a lot of variables. If you started with the full brick of coir the final appearance will also depend on how much other food You've mixed in. Coir as a component of the compost is great and it will eventually breakdown. If it's mostly coir though it will take longer and it won't look quite the same.

My first tray took about 2-3 months of maturing before I was satisfied with it. I had a few scraps of paper and a few peanut shells that didn't break down but the rest was very good quality. I left my first tray alone without adding more food to it for 2-3 months and only added food to the new trays for that time. My rational was to allow the worms to continue to mature and eat on the tray without being disturbed. I started with 1000 worms and I'm still trying to grow my population. I think the general guidance I've found is about 1000 worms per tray but that number varies by who's quoting it. (I'm also assuming you have a worm factory or similar system).

If you need to continue to add more scraps (because you don't have anywhere else to put them) I'd suggest either freezing the scraps for a while or composting in a more traditional way outside. You can use the traditional compost as feed for the worms since it's just breaking down what they'd be given anyhow. When you add the next tray to your system, you're in effect dividing the population and the number of worms working on your first tray will be reduced. Which is another reason to add new material slowly. Usually some worms will stay in that tray and continue working but the rate will be reduced until the population increases.

If you decide to start your next tray I would suggest almost forgetting the first tray for a few months. Too much time won't hurt anythig but you'll end up with good quality castings