Pineapple Pickles

1 (20 ounce) can pineapple chunks
3/4 cup cider vinegar
1 cup granulated sugar
6 whole allspice berries
3 whole cloves
1 (3-inch) stick cinnamon
Dash of salt
Red food coloring (optional)

Drain pineapple, reserving 3/4 cup syrup. Put syrup and all ingredients except pineapple and food coloring  into saucepan. Cook uncovered 15 minutes. Remove from heat and add 1 to 2 drops food coloring. Cool and pour over pineapple. Put into jar, cover tightly, and refrigerate at least 24 hours.