Vignette
A vignette (dark edges) can be added around an image. You're able to control the amount of vignette and its color.
'vignette.value' controls how far into the image the vignette appears. It is set with a number from 0 to 100. The default is 20.
https://demo.sirv.com/vase.jpg?vignette.value=50
'vignette.color' sets the color of the vignette. The values are set with hex RGB/RGBA or an HTML color name.
https://demo.sirv.com/vase.jpg?vignette.color=red
If you set the color with a hex value, don't include a '#' character in the URL. For example:
https://demo.sirv.com/vase.jpg?vignette.color=ff0000
Here are examples of 'vignette.value' and 'vignette.color' together:
https://demo.sirv.com/vase.jpg?vignette.color=blue&vignette.value=50
https://demo.sirv.com/vase.jpg?vignette.color=ff8c00&vignette.value=100
https://demo.sirv.com/vase.jpg?vignette.color=ffffff&vignette.value=40