Created attachment 140503 [details]
The tray icons of VLC and Electrum are affected by the problem

The recent upgrade from MESA 17.2.8 to 18.0.5 is causing the icons of some applications bundled with Ubuntu 16.04 to be displayed incorrectly in the status bar. The icons are surrounded by a shadow (or a black background) and some colorization is missing.
The problem can be seen on the attached picture - VLC and Electrum icons are affected by the problem (VLC's icon is surrounded by an extra shadow and Electrum icon is supposed to be blue but is all black), and HexChat's icon is displayed correctly next to them.

I'm using Linux Mint MATE 18.3 (based on Ubuntu 16.04's package base), but the problem is present on Ubuntu MATE 16.04, too. The hardware i'm using is ThinkPad T400 with an integrated Intel graphic accelerator, using the default intel Xorg driver.

$ lspci -k | grep -EA3 'VGA|3D|Display'

00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
 Subsystem: Lenovo Mobile 4 Series Chipset Integrated Graphics Controller
 Kernel driver in use: i915
 Kernel modules: i915
00:02.1 Display controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
 Subsystem: Lenovo Mobile 4 Series Chipset Integrated Graphics Controller
00:03.0 Communication controller: Intel Corporation Mobile 4 Series Chipset MEI Controller (rev 07)
 Subsystem: Lenovo Mobile 4 Series Chipset MEI Controller

$ glxinfo | grep -i vendor

server glx vendor string: SGI
client glx vendor string: Mesa Project and SGI
Vendor: Intel Open Source Technology Center (0x8086)
OpenGL vendor string: Intel Open Source Technology Center