[PATCH v5 4/7] perf config: Use combined {fore,back}ground colors value instead of each two color

To manage all default config values at one spot (at util/config.c), it would be better that actual variables for each 'colors' config also have only one value like 'default_config_item' type. If we do, it smoothly work to initialize 'colors' default config values by 'colors_config_items' array

[PATCH v5 4/7] perf config: Use combined {fore,back}ground colors value instead of each two color

To manage all default config values at one spot (at util/config.c), it would be better that actual variables for each 'colors' config also have only one value like 'default_config_item' type. If we do, it smoothly work to initialize 'colors' default config values by 'colors_config_items' array