as a general rule, when the pods turn red (or their true ripe color), they are "sweeter" than when green...however, I love my green corked jalapenos...
it is actually up to you when you pick...immature green pods do not have near the heat level as mature green pods do...
if you want the pods at their hottest, pick them when the first blush of "ripe" color appears...I can't find the link but I read a scholarly article about "when peppers are their hottest"....
tabascos that are used for pepper sauce are usually yellowish in color, but the standard tabasco sauce uses red pods...
the color of the pods generally determine the color of the sauce unless the color is covered up by other things such as plums or other deeply colored fruits...
+1 for ripening pods off the vine not as good as on the vine...