duotone* effect to the image.
The parameters are, in order:
Colors can be expressed in any accepted format.
If an opacity is given, a semi-transparent version of the duotone image will be composited with the original image. This way the original colors will be visible under the choosen tones.
With opacity at 0.6
An opacity of 0.6 is used here, so original colors are visible:
This effect is borrowed by
gatsby-plugin-sharp and inspired by articles like
duotone in js