weseek__growi/resource/styles/scss/theme/default.scss

// import to read variables
@import '../../agile-admin/inverse/colors/default';

// apply agile-admin theme
@import '../../agile-admin/inverse/style';

// import again to apply colors
@import '../../agile-admin/inverse/colors/default';

// override
@import 'override-agileadmin';