Undefined operation with adding 2 colors

[kays-chetoui]

[nex3]

This is intended. Color arithmetic is no longer supported--see #2144 for details. If you want to mix two colors together, we recommend using the mix() function.

[geocolumbus]

The documentation still indicates you can add RGB colors with +. In Section 6, for example.

https://sass-lang.com/documentation/file.SASS_REFERENCE.html#sassscript

[nex3]

@geocolumbus That's fixed in the new documentation being added in sass/sass-site#205.