[[MetaPost]] only supports the RGB color space, although with the help of [[MetaFun]] you can face transparency and CMYK colors. This article describes the use of colors in MetaPost and MetaFun.
* (If you are not using the standalone, regenerate your TeX with {{code|sudo update-texmf}})
* Lastly, regenerate the MetaFun format with {{code|texexec --make}}. Transparency should work now.