How to enable dark mode for GTK apps?

Support GNOME
1

I am using Manjaro Gnome edition. I am using default Matcha Dark theme. But some apps doesn’t enable dark mode. Like vlc, smplayer. tried changing theme… but doesn’t work. Any help?

Screenshot from 2020-09-28 03-20-38
Screenshot from 2020-09-28 03-20-381366×768 47.7 KB
Screenshot from 2020-09-28 03-21-22
Screenshot from 2020-09-28 03-21-221366×768 282 KB

#################### inxi -Fxzc0 ########################

    System:    Kernel: 5.8.6-1-MANJARO x86_64 bits: 64 compiler: N/A Desktop: GNOME 3.36.6 
               Distro: Manjaro Linux 
    Machine:   Type: Laptop System: ASUSTeK product: X550JK v: 1.0 serial: <filter> 
               Mobo: ASUSTeK model: X550JK v: 1.0 serial: <filter> UEFI: American Megatrends 
               v: X550JK.304 date: 04/16/2019 
    Battery:   ID-1: BAT0 charge: 11.0 Wh condition: 11.2/32.6 Wh (35%) model: ASUSTeK X550A30 
               status: Not charging 
    CPU:       Topology: Dual Core model: Intel Core i5-4200H bits: 64 type: MT MCP arch: Haswell 
               rev: 3 L2 cache: 3072 KiB 
               flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 22356 
               Speed: 3179 MHz min/max: 800/3400 MHz Core speeds (MHz): 1: 3151 2: 3150 3: 3150 
               4: 3148 
    Graphics:  Device-1: Intel 4th Gen Core Processor Integrated Graphics vendor: ASUSTeK driver: i915 
               v: kernel bus ID: 00:02.0 
               Device-2: NVIDIA GM107M [GeForce GTX 850M] vendor: ASUSTeK driver: nvidia v: 450.66 
               bus ID: 01:00.0 
               Device-3: Realtek USB Camera type: USB driver: uvcvideo bus ID: 1-7:5 
               Display: x11 server: X.org 1.20.8 driver: modesetting,nvidia 
               resolution: <xdpyinfo missing> 
               OpenGL: renderer: GeForce GTX 850M/PCIe/SSE2 v: 4.6.0 NVIDIA 450.66 direct render: Yes 
    Audio:     Device-1: Intel Xeon E3-1200 v3/4th Gen Core Processor HD Audio driver: snd_hda_intel 
               v: kernel bus ID: 00:03.0 
               Device-2: Intel 8 Series/C220 Series High Definition Audio vendor: ASUSTeK 
               driver: snd_hda_intel v: kernel bus ID: 00:1b.0 
               Sound Server: ALSA v: k5.8.6-1-MANJARO 
    Network:   Device-1: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter vendor: AzureWave 
               driver: ath9k v: kernel port: e000 bus ID: 03:00.0 
               IF: wlp3s0 state: up mac: <filter> 
               Device-2: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet vendor: ASUSTeK 
               driver: r8169 v: kernel port: d000 bus ID: 04:00.1 
               IF: enp4s0f1 state: up speed: 100 Mbps duplex: full mac: <filter> 
               IF-ID-1: Wireguard-WARP state: unknown speed: N/A duplex: N/A mac: N/A 
    Drives:    Local Storage: total: 1.02 TiB used: 65.19 GiB (6.2%) 
               ID-1: /dev/sda vendor: Western Digital model: WDS120G2G0A-00JH30 size: 111.80 GiB 
               ID-2: /dev/sdb vendor: Seagate model: ST1000LM024 HN-M101MBB size: 931.51 GiB 
    Partition: ID-1: / size: 109.25 GiB used: 14.80 GiB (13.5%) fs: ext4 dev: /dev/sda2 
    Swap:      ID-1: swap-1 type: file size: 4.00 GiB used: 0 KiB (0.0%) file: /swapfile 
    Sensors:   System Temperatures: cpu: 97.0 C mobo: N/A gpu: nvidia temp: 74 C 
               Fan Speeds (RPM): cpu: 25500 
    Info:      Processes: 311 Uptime: 2h 29m Memory: 7.66 GiB used: 3.40 GiB (44.3%) Init: systemd 
               Compilers: gcc: 10.2.0 Packages: 1244 Client: shell wrapper v: 5.0.18-release 
               inxi: 3.1.05
2

those aren’t gtk apps. Open kvantum and set their theme there.

3

Qt-based applications have to be configured separately, through qt5ct, and for more fancy results, in combination with a kvantum theme. :wink:

4

thnx. it worked.

5

That’s actually not used anymore on GNOME. QGnomePlatform has replaced it. Looks better and no need for fiddling. Kvantum Manager is optional, but is still used to override the Qt Style.