It’s true that you can’t edit things in the future, it’s just using the same relative date range system.
The parameter is the same as the “UNTIL”. You didn’t get results because you didn’t set any dates, I guess.
For more Until, Since, and Within, see this post: What are the differences between the operators "within", "until", and "since"?
That would be an absolute date range, which will be introduced in this future.
Can you be a bit more specific? Search queries like “color:blue” works fine both on desktop and on web for me. Have you set color labels?