What Would Sargent Do?

 John Singer Sargent, genius master of loose, brushy painting, has two works titled "A Street In Venice." I'm trying to capture their overall outdoor atmosphere here in this little painting of two waiters conversing during a break. The streets that Sargent featured are mostly done in neutral colors, but I'm scrutinizing them for alternate hues that liven things up. 

Working with a grid yesterday was a disaster. I'm trying to draw in freehand at this point, but what a mess...

                                                                            A Street In Old Town, work in progress (click on image for larger view)