There was a suggestion in anmother thread that settling diofferences with Austria over Italy in the 1850s or early 1860s could avoid a Franco-Prussian War. With Italy defused, Prussia contained and Alsace-Lorraine safely French, colonial expansion would likely be both more feasible and less controversial in the last third of the century. Of course, barring a carve-up of the Sinosphere I don't think there was much valuable territory still to be had, but I could easily see bigger pieces of Africa and the Pacific going French.