Mix first three ingredients in a large saucepan. Stir over medium heat until sugar dissolves. Boil, without stirring until temperature reaches 310 degrees or until drops of syrup form hard, brittle threads in cold water. Remove from heat. After boiling has ceased, stir in flavoring and coloring. Pour onto lightly greased cookie sheet. Cool and break into pieces. Dust with powdered sugar, if desired. Store in airtight containers.