What is the best way to display properties on an editor?

A little bit of context to make my self more clear. I am working on software tool that is meant for designing UIs. My next step is to create a properties area, where you edit the width/height, x/y, font colour, the action of the element, and other options.

I believe that the best way to do that is by grouping the different options to related tabs, for example one tab for Colour where you can set the different colours, one for size, one for other etc. (see picture below)

My manager on the other hand believes that this will make it slow and we should have all options together displayed in one tab. I managed to convince him that this is not a good approach. But his new suggestion was just create to tabs and split them to half. (see picture below)

I believe that the best approach is multiple tabs, grouping the different kind of options.

My question is am I right on this? if yes what other arguments could I use? if not, what would be a better approach?