The consensus is that it is not appropriate for a gentleman without colors to wear scarlet at formal occasions.
In your case, since you have been awarded colors (congratulations!!!) but it is not customary for a gentleman to wear scarlet, you request permission to wear scarlet.
Either way - you request permission as it is not customary.
If a gentleman without colors, or who has been awarded colors but it is not customary for members to wear scarlet, and he’s dressing for a formal occasion, he wears a black tailcoat with white tie and facing.
Unless it is a black tie or semi-formal event in which case a tuxedo is appropriate.
This is just plain etiquette, long established traditions that go far beyond foxhunting - formal occasions for a hunt club just usually follow standard etiquette for formal occasions.
Since hunt clubs do develop their own particular customs over time (some clubs go back over 100 years), you’ll see some variations in things like buttons and whatnot.
So, unless YOUR hunt club has granted you permission to wear scarlet at a formal event, you do not wear it.
You wear the clothing suitable for a gentleman attending a formal or semi-formal event.
At High Holy Days a gentleman with colors who does not wear scarlet would wear a weaslebelly with colors on the collar.
(which is extremely elegant :yes:)
Or he could wear a frock. (It’s certainly cheaper than collecting different coats for different occasions…)
you know, all this talk makes looking for a formal gown look a lot less complicated. :lol: