Switch to a better theme for light background terminals

The following snipped can be placed in a configuration file, and provides an alternative theme more suitable to be used with light background terminals.

dashboard -style style_selected_1 '47;1'
dashboard -style style_selected_2 '47'

dashboard -style style_high '34'
dashboard -style style_low '30;1'
dashboard -style style_error '31'
dashboard -style style_critical '31;7'

dashboard -style divider_fill_style_primary '36'
dashboard -style divider_label_style_on_primary '34;1'
dashboard -style divider_label_style_off_primary '34'

dashboard -style divider_fill_style_secondary '30'
dashboard -style divider_label_style_on_secondary '30'
dashboard -style divider_label_style_off_secondary '30;1'

dashboard -style syntax_highlighting 'xcode'

This theme has been adapted from a suggestion by Stefan Tauner.