color:darken_based_on_luma_difference_between_another_color

Will darken the color until the minimum desired luma difference is reached between the two colors

color:darken_based_on_luma_difference_between_another_color(STRING $hex_color_code, STRING $another_color_hex_code, INT $minimum_desired_luma_difference)

color:darken_based_on_luma_difference_between_another_color('160502', '000', 100)        
#=> "#030000"