Wool

Wool is a decorative block. It comes in many variants and colours.

Variants
Wool comes in many colours. Here is their order of appearance in the block select menu, and their block IDs:
 * Red (21)
 * Orange (22)
 * Yellow (23)
 * Lime (24)
 * Green (25)
 * Aqua (26)
 * Cyan (27)
 * Blue (28)
 * Purple (29)
 * Indigo (30)
 * Violet (31)
 * Magenta (32)
 * Pink (33)
 * Black (34)
 * Grey (35)
 * White (36)