xrandr gives black background

Question

I use Ubuntu 12.04 on a Toshiba Portege R600. Normally I have a flat green background (the middle choice of the custom set under wallpapers in the right-mouse-click GUI).

When I plug in a VGA monitor for two-screen usage the background on that and on the laptop screen go black. They remain black after I unplug the monitor and give the command:

xrandr --output LVDS1 --auto --output VGA1 --off

Is there a trick to maintain the green blackground, at least on the laptop screen, or at least regain it automatically on the laptop screen?

Per OP, resolved by upgrading: "This bug went away when I installed Ubuntu 14.04 on a new Toshiba Z930." — belacqua, May 12 '14 at 19:14

Radu Rădeanu · Answer 1 · 2013-10-11T13:18:24.570

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An workaround will be to use the following command:

xrandr --output LVDS1 --auto --output VGA1 --off && gsettings set org.gnome.desktop.background primary-color "#73D216"

This will set again your background color to #73D216 (green).

edited Oct 11 '13 at 13:18

answered Oct 11 '13 at 11:55

Radu Rădeanu

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Thanks but no go: DISPLAY=:0: Command not found. Sorry, should have added I use Gnome Classic. – Rob Rutten Oct 11 '13 at 12:54
@RobRutten Are you sure that you copy it correctly? Dont't use any space before or after `=` sign. – Radu Rădeanu Oct 11 '13 at 13:00
alias vga-off 'xrandr --output LVDS1 --auto --output VGA1 --off && DISPLAY=:0 GSETTINGS_BACKEND=dconf gsettings set org.gnome.desktop.background primary-color "#73D216"' – Rob Rutten Oct 11 '13 at 13:06
Or is it my use of tcsh? Sorry, I am not too unix-knowledgeable... – Rob Rutten Oct 11 '13 at 13:12
@RobRutten Oh... tcsh. Ok, don't use these variables `DISPLAY=:0 GSETTINGS_BACKEND=dconf`. See if it is working with `gsettings set org.gnome.desktop.background primary-color "#73D216"` only. – Radu Rădeanu Oct 11 '13 at 13:20
Yes, that's it! Many thanks! Is there a palette or such to choose a color specifying such code number? – Rob Rutten Oct 11 '13 at 13:47
@RobRutten Yes, you can use [gcolor2](http://askubuntu.com/a/351470/147044). If this answered your question, you may [mark this answer as accepted](http://askubuntu.com/help/someone-answers), by clicking the green check mark next to it. That will indicate that your problem is solved. – Radu Rădeanu Oct 11 '13 at 13:50
Hold! I found a nifty color code finder at http://www.colorpicker.com/ Question closed- Thanks! – Rob Rutten Oct 11 '13 at 13:58
@RobRutten Well, are many useful tools in this sense. – Radu Rădeanu Oct 11 '13 at 14:01
Sorry! I was too quick. The gsettings background color definition only works after I have manually reset the background with the GUI. After switching off or unplugging he second VGA monitor the background stays black also when apply your command. he gestetings command – Rob Rutten Oct 12 '13 at 08:50
Then run again `gsettings set org.gnome.desktop.background primary-color "#73D216"` only. – Radu Rădeanu Oct 12 '13 at 08:52
I tried that. The background stays black. If I reset it with the GUI then after that the command does work. – Rob Rutten Oct 12 '13 at 10:29
@RobRutten Maybe you have a bug. That command will not work if you have an image set as background. – Radu Rădeanu Oct 12 '13 at 10:36
@ Radu Radeanu I don't use an image but the central lightgreen "custom" flat background in the Appearance GUI. I tried instead with an (ugly) wallpaper from upper choice in the GUI: xrandr then works properly, giving that background on both screens and keeping it after unplugging or my vga-off. With the flat choice and your command above the green flashes momentarily into view when I unplug and then the background goes black and stays black, the command won't work afterwards either - until I revive the GUI choice and then it does work. Some real bug I suspect. Thanks anyhow! – Rob Rutten Oct 12 '13 at 13:20
@RobRutten Sound like a bug. See [How do I report a bug?](http://askubuntu.com/questions/5121/how-do-i-report-a-bug). – Radu Rădeanu Oct 12 '13 at 14:17

score 0 · Answer 2 · answered May 12 '14 at 18:47

0

This bug went away when I installed Ubuntu 14.04 on a new Toshiba Z930.

answered May 12 '14 at 18:47

Rob Rutten

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xrandr gives black background

2 Answers2