I know these things are personal opinion and I know FMInc has to keep updating styling to keep FM looking fresh and modern .. BUT ...
IMHO, the Arrange & Align icons in the inspector in FM15 are a real downgrade. They have changed from being colour to being greyscale and they have new designs. For a new user I reckon they would be harder to understand what each one means.
Strangely the icons in layout mode in the toolbar for adding various objects to the layout etc. have changed from greyscale in FM14 to colour in FM15. Inconsistent design / styling changes from one part of the interface to another. Not sure what is going on there.