[widgets][toolchaineditor] removed unwanted additional channel color

Fixes #267
4 jobs for 267_toolchain_additional_unwanted_channel_color in 20 minutes and 39 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #201372
docker
build_linux_36

00:10:08

90.0%
passed #201373
docker
build_linux_37

00:09:54

90.0%
passed #201370
macosx
build_macosx_36

00:20:39

90.0%
passed #201371
macosx
build_macosx_37

00:08:30

90.0%