I talked to a Mexican guy who help the neighbor with some yard work. He saw my
Serano pepper plants (they stay green too) and he showed me how they fill out,
and lose this sort of dull green color. They get plump and really shiny when
they are ready to go.

My advice is to pick them too early rather than too late. If you keep them on
the plant too long, they stop fruiting.

The jalepenos and habeneros are a lot easier, they turn from green to orange or
red.

I understand the peppers are hotter when FULLY ripe, but if I pick the Seranos
a little unripe, they are still PLENTY hot for me, and make sure the plants
keep flowering and setting fruit. And pat is right. They also like to rot, or
get so heavy they start to tear limbs off the plants.

what kind of hots do you grow? You might look it up and see what ripe ones
look like.

There are some good sites, one, i think, is called " chilihead.com " or
something like that.