You can install it using the excellent Package Control package manager for Sublime Text:
Open "Package Control: Install Package" from the Sublime quick menu (Command-Shift-P), then select this Nintendo Switch theme.
Sublime Text / Preferences / Browse Packages …
THEMES
Nintendo Switch.tmTheme
to THEMES
Sublime Text / Color Schemes / THEMES / Nintendo Switch.tmTheme
to use it"highlight_modified_tabs": true,
"theme": "Adaptive.sublime-theme",