See also similar pull request.

1. Behavior before pull request

New color scheme User/SashaSublime (SublimePythonIDE).tmTheme create and replace current color scheme in User/Preferences.sublime-settings after Sublime Text restart.

2. Behavior after pull request

New color scheme don't generate and don't replace current color scheme.

3. Reasons

1. Users may well manually add these lines in tmTheme file of user preferred scheme.
2. I am color scheme developer. Each time, when I need to change my color scheme, I need change in my User/Preferences.sublime-settings file "color_scheme": "Packages/SashaSublime/SashaSublime.tmTheme" to Packages/User/SashaSublime (SublimePythonIDE).tmTheme. It takes a lot of time.
3. Some Sublime Text packages also generate own color schemes. Examples:

• PersistentRegexHighlight,
• Color Highlighter,
• SublimeLinter3,
• Colorcoder.

Each of these packages create own color scheme. But user may use one color scheme. Color changes of other packages don't applied.

1. I think, is a bad practice — impose user file your color scheme without the user's permission.

4. Alternative

You may add option generate_new_color_scheme_file in settings. If false, new color scheme file don't generate.

Thanks.