I would like to change the dark theme of mission planner… it have default dark background in theme manager. But the changes didn’t reflect when I build the application. What should I do the change the back color in theme.? Please help me.
You are poking around at the wrong place 
From release 1.71 the color theming possibilities has been changed in Mission Planner. The previous fix coded themes have been replaced with external theming files and an integrated theme file editor to edit these files.
There are two types of theme files. The ones with .mpsystheme extension are resides in the installation directory and part of the Mission Planner installation. At this moment the BurntKermit and HighContrast themes are implemented this way. Besides the system themes there are user theme files with .mpusertheme extension. They located in the user data directory alongside with other config files.
System themes are read only, but they can be copied into a new user theme for editing.
System and User themes are enumerated at startup and you can choose theme from the Config/Planner tab, just like in older versions of Mission Planner. The chosen theme name is stored in Mission Planner config file. If the configured theme file is missing, then the system falls back to BurntKermit theme.
The “custom” button besides the theme selector drop down box in config panel invokes the theme editor to edit the currently selected theme.
To create a new theme, based on the actual one, click the “Create Copy” button. The new theme will be created with .mpusertheme extension in the user data directory.
Thanks a lot sir. I have changed the theme
were you able to create your own or did you take the high contrat one ? If you did your own could you could you explain how ?