Most adult wardrobes are 60-80% black, navy, and grey. The defaults feel safe but produce monotonous wardrobes that don't flatter most skin tones equally and lack visual interest.
What adding one or two colours does
One signature colour that suits your skin tone (camel, burgundy, forest green, navy variations beyond black) transforms wardrobe variety and outfit interest. Test colours against your skin in natural daylight, not shop fluorescents.
You don't have to abandon black. Adding 2-3 colour pieces that genuinely suit you usually shifts wardrobe satisfaction noticeably within a season.