fix(color): fixed branch error when calling getPluginColor('error')

[liangmiQwQ]

Problem

We expect to get the return value from getHsla when calling getPluginColor with the any keys in predefinedColorMap

It works most of the time, but it will use getHashColorFromString when calling getPluginColor('error') although error is a key of predefinedColorMap

Fixes

Fixed the above issue by correcting filtering undefined method

[liangmiQwQ]

one more thing: I will create some tests for the situation like this