beautiful, brilliant, glorious, gorgeous, lovely, spectacular, stunning
fiery, golden, orange, red

admire, watch

against the sunset
The trees were black against the sunset.

at sunset
We walked along the beach at sunset.

sunset over
a beautiful sunset over the bay

the glow of the sunset
They sat in the last glow of the sunset.

ride off into the sunset, sail off into the sunset (both usually figurative)
At the end of the movie, the hero rides off into the sunset.

Sunset is used with these nouns:
provision