PH: A Rainbow of Postcards

Thanks to @shirleyinCA for this swap suggestion.

Send your partner three (3) blank postcards in an envelope - each card will be predominantly one color.
eg.
-a big red barn or a garden of red roses for RED
-pumpkins or lady in an orange dress for ORANGE, etc.

The typical rainbow is RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE. Choose three different colored pcs to send from the rainbow colors listed.

Postcards should be unwritten and unstamped. They should be store bought only and of good quality. (No handmade/freebie/ad/zazzle). Sender's choice.