Bullk annotations disappear when changing their colour

[CPBridge]

I can get bulk annotations (Microscopy Bulk Simple Annotations) to display correctly in Slim (if I use frame of reference coordinates). They show up as points in a turquoise colour. However, when I try to change their colour using the sliders under the "annotation groups" panel on the right, they instantly disappear and no matter when I can do I cannot get them back without reloading the entire study.

I am using current master branch (commit 54b4fb4), MacOS, and have reproduced the same behaviour in both Firefox and Chrome.

@fedorov @DanielaSchacherer @dclunie @cgorman