[windows] テキストの一部色を変更したいとき、スポイトツールを使えない（全文変わってしまう）

Hi, I've used the translate feature so I hope I'm answering your query correctly.
Your description of what is happening appears to be an intended result, as mine behaves the same way.
As an alternative are you able to select content with the colour you want then add that as a colour to your assets? In this way you would be able to select specific text and make sure you were getting the same colour each time.