Undo/Redo button highlighting is inverted

Description

When at the latest change, the redo button isn't available. However, it looks "active" compared to the adjacent icons. The icons which appear "inactive/greyed-out" are the available actions. This seems a bit backwards to me. My guess is that this is due to the dark theme.

image

KiCad Version

Application: Footprint Editor

Version: (5.99.0-7778-g61ac9c8d90-dirty), debug build

Libraries:
	wxWidgets 3.0.5
	libcurl/7.68.0 GnuTLS/3.6.15 zlib/1.2.11 brotli/1.0.9 libidn2/2.3.0 libpsl/0.21.0 (+libidn2/2.3.0) libssh/0.9.3/openssl/zlib nghttp2/1.41.0 librtmp/2.3

Platform: Linux 5.8.0-7630-generic x86_64, 64 bit, Little endian, wxGTK, pop, x11

Build Info:
	Date: Dec 23 2020 13:31:45
	wxWidgets: 3.0.5 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
	Boost: 1.71.0
	OCE: 6.9.1
	Curl: 7.68.0
	ngspice: 32
	Compiler: GCC 10.2.0 with C++ ABI 1014

Build settings:
	KICAD_SCRIPTING=OFF
	KICAD_SCRIPTING_MODULES=OFF
	KICAD_SCRIPTING_PYTHON3=OFF
	KICAD_SCRIPTING_WXPYTHON=OFF
	KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
	KICAD_SCRIPTING_ACTION_MENU=OFF
	KICAD_USE_OCE=ON
	KICAD_SPICE=ON
	KICAD_STDLIB_DEBUG=OFF
	KICAD_STDLIB_LIGHT_DEBUG=OFF
	KICAD_SANITIZE=OFF