The default file types icons have changes from EAP 2016 163.4830.18 to 2016.3 EAP (163.6512.15). The new ones have a grayscale look whereas the former ones had a yellow border.
Please for the love of god allow the user to change which icon set they want to use. i.e. Legacy or Classic look, or modern 2016.3 EAP style.
The new style is not necessary. It is difficult to read. I prefer the older style since the contrast is better on the screen. There doesn't seem to be a way to revert to the classic look.
Either add a classic look option or drop the grayscale style, it is horrible!