openrgb-systemd-unit/systemd/user/openrgb.service

[Unit]
Description=OpenRGB control

[Service]
Type=simple
ExecStart=%h/bin/OpenRGB/OpenRGB -c 00FFFF -m Static
ExecStop=%h/bin/OpenRGB/OpenRGB -c 000000 -m Static
RemainAfterExit=yes

[Install]
WantedBy=default.target