blue
Anyone can join, with a 50-word vignette in the comments. Your vignette does not have to include the prompt term.
My efforts:
The corridor was blue. It had been bright sky blue when first she came. Now it had turned slate blue. She wondered how long it would take before it was gray, and whether the dragon would, in due course, leech the color from the sky.
She reached the lab's door.
A swirl of blue appeared ahead of her. Artemise froze. And then she hurried forward.
"Ciara!"
The other woman, dressed like her but black-haired, whirled around, drawing her rapier, and Artemise pulled back. But a moment later, Ciara, pale, put up the sword and said, "You got it!"
Artemise nodded.