How to use "darker" in a sentence

'I'm Megan,' says the darker girl, 'and this is Kristi.'

And so he waits, and the evening becomes darker, and he thinks that there are now only one or two people left in the small old church

Meanwhile, the sky grew darker by the second; massive storm clouds, like the clenched fists of celestial giants, squeezed the last light out of the day

Gradually Michael's displeasure over her desire to succeed was complicated by a darker emotion: He grew jealous of her smallest achievements

She thought of the man in her nightmare, the man in black whose face had been lumpy with maggots, and the shadows in the corner of her office seemed darker and deeper than they had been a moment ago.

Even a primarily good government, when it's big enough, has some pretty mean sharks swimming in the darker currents