If I’m understanding correctly, you can set the foreground:
This would set the foreground yellow (old sublime text color scheme):
<!-- Brackets -->
<!-- It's not possible to set the background for brackets.
See https://github.com/SublimeTextIssues/Core/issues/2123. -->
<key>bracketsOptions</key> <string>foreground</string>
<key>bracketsForeground</key> <string>#e6db74</string>
<key>bracketContentsOptions</key> <string>foreground</string>
<key>bracketContentsForeground</key> <string>#e6db74</string>
In newer versions of Sublime Text you can use overrides, for example install MonokaiFree and create a custom override with:
{
"globals":
{
"brackets_options": "foreground",
"bracket_contents_foreground": "foreground"
},
"rules":
[
]
}
That will make the foreground of brackets yellow. See https://github.com/gerardroche/sublime-monokai-free/pull/4#issuecomment-418126044 for details on creating overrides.