If a player has a multi-colored Feather card, and the required color is one of the colors on it, then it is counted as always showing the required color. If the Feather has none of the required colors, then the player chooses an available color from the feather.
If a multi-colored card is played first, then the player chooses the color from the colors on that Feather.
When revealing a multi-colored Feather card as a Trump card, that round has no Trump color.