Grease baking sheet; set aside.

Wash and dry apples; remove stems and insert skewers into stem ends.

In a heavy 2-quart saucepan, stir together sugar, cream of tartar, water and lemon juice; stir over medium heat until sugar is dissolved. Add coloring. Bring to a boil and continue cooking, without stirring, until temperature reaches 310°F on candy thermometer (hard crack stage).

Remove from heat. Twist apples in syrup quickly. Set on prepared baking sheet. Use same day as prepared.

Hard crack stage is when a small amount of mixture is dropped into very cold water and it forms brittle threads.