Peaches I canned are browning. I followed the directions... what happened?

I have frozen peaches before and I have canned tomatoes for many years. This year I canned peaches (about 3 months ago). I used a medium syrup and followed the directions completely. I looked at all my jars and they seem to be turning slightly brownish. I opened a jar and there is an odd smell, sort of like tea. The peaches at the bottom of the jars (totally immersed in syrup) are a normal color. I am uming the peaches are going bad, correct? Any ideas why? Do the peaches need to be totally immersed in syrup in order not to spoil? I thought that the water bath cooking and proper sealing would take care of that.