[Feature proposal]: Reuse same color for multiple labels

[saroad2]

Consider the following labels.toml file:

[linux]
color = "25d4dd"  # platform label
name = "linux"
description = "The issue relates Linux support."

[macOS]
color = "25d4dd"  # platform label
name = "macOS"
description = "The issue relates to Apple macOS support."

[windows]
color = "25d4dd"  # platform label
name = "windows"
description = "The issue relates to Microsoft Windows support."

As you can see, some of the platforms have the same color intentionally. This is due to the reason that they represent the same type of label. It would be nice if one could do the following:

[colors]
platform = "25d4dd"

[linux]
color = "platform"
name = "linux"
description = "The issue relates Linux support."

[macOS]
color = "platform"
name = "macOS"
description = "The issue relates to Apple macOS support."

[windows]
color = "platform"
name = "windows"
description = "The issue relates to Microsoft Windows support."

What do you think? Once you approve, I will implement it.