Harry looked down and saw deep green mountains and lakes, coppery in the sunset.

Twilight fell: The sky turned to a light, dusky purple littered with tiny silver stars.

Forming and breaking in the sky, I fancy all shapes are there; Temple, mountain, monument, spire; Ships rigged out with sails of fire, And blown by the evening air.

The sun had set, but a faint pastel haze lingered in the mid-summer sky.

And though I came to forget or regret all I have ever done, yet I would remember that once I saw the dragons aloft on the wind at sunset above the western isles; and I would be content.

There's no formula.