@ derv, great call. Just did. But if there is anyone with any idea of how syntax highlighting works, I'd like to know if this is a change that needs to be made deep in the guts of RStudio or if it can be made in CSS or something. I observe that highlighting styles vary considerably in what they choose to identify, and hoping that is because the differences are not so hard.
A visual comma-period descriminator would also be welcome.