The leaves behind these, that are more in the shade, appear greener, and have less spots. However, they look like they are yellowing.

Valisa,
You kind of identified the issue yourself by stating the leaves that are more in the shade appear greener and have less spots. The yellowing and spotting is caused by a lot of light; yours appears to be caused by direct sun (I don't believe the leaves will fall off, but appear a bit less attractive than you might like).

Planto

looks like Erwinia carotovora bacterial leaf spot

I don't know anything about the leaf spot HL refers to, but I think it does look washed out from too much sun. Put it in a shady spot and the leaves will green back up.

Denise in Omaha