* Gold: Often associated with age, wisdom, and the celebration of a long life.
* Silver: Another traditional color for anniversaries, representing the passage of time and the brilliance of experience.
* Purple: A color often associated with royalty and wisdom, making it a good choice for a 75th birthday.
* Warm colors: Like orange, yellow, and red, could symbolize energy, enthusiasm, and the warmth of long-lasting relationships.
* Blue: Representing peace, tranquility, and a life well-lived.
Ultimately, the "color motif" for a 75th birthday is a matter of personal preference. Consider the individual's personality, interests, and what they would enjoy.