You have not heard my love's dark throat
Slow-fluting like a reed,
Release the perfect golden note
She caged there for my need.
Her walk is like the replica
Of some barbaric dance
Wherein the soul of Africa
Is winged with arrogance.
And yet so light she steps across
The ways her sure feet pass,
She does not dent the smoothest moss
Or bend the thinnest grass.
My love is dark as yours is fair,
Yet lovelier I hold her
Than listless maids with pallid hair
And blood that's thin and colder.
You-proud-and-to-be-pitied one,
Gaze on her and despair,
Then seal your lips until the sun
Cullen surely has in mind here Shakespeare’s  Sonnet 130  (“My mistress' eyes are nothing like the sun”), which also celebrates a darker woman’s beauty against a prevailing beauty standard that fetishizes pallor and “fairness”: 
 If snow be white, why then her breasts are dun; If hairs be wires, black wires grow on her head… And yet, by heaven, I think my love as rare As any she belied with false compare. 
 Cullen goes further than Shakespeare, actually criticizing the looks and temperament of paler women.