Those green pods are full of seeds. They don't turn brown when ripe, just kind of yellowish. Then they explode! When I think they are getting ripe, I give them a very gentle squeeze. If they are ripe, the pod will pop open with very little pressure (hold your hand under the pod). The seeds will be white if it's too early and brown if ripe. Keep your eye on them or you will have tons of balsam next year from exploded pods.

It's so fun to collect these seeds - Nurmey is right! Just give em a little squeeze and if they are ready they will pop.

Ripe seeds are brown, but I have had germination from seeds that are brown/yellow when harvested. Brown is best of course, I just wouldn't throw out the seeds that fall in between.