1
What is your favorite color?
Point to the person to sign YOU, sign FAVORITE, and then sign COLOR by bringing your open '5' hand to your chin and wiggling your fingers. Remember to furrow your eyebrows at the end to indicate a 'wh-' question.
2
I like many colors.
Point to yourself for I, sign LIKE, and then sign COLOR by fluttering your fingers at your chin. Just as the description mentions, follow this immediately with the sign for MANY to show plurality.
3
My car is a different color.
Sign MY CAR, then perform the sign for COLOR with your palm facing your body and fingers wiggling at the chin. Finish with the sign for DIFFERENT to complete the thought.