Uppercase Letter X Color-by-Letter Worksheet Worksheet.Fill your child's life with colors! The <em>Uppercase Letter X Color-by-Letter Worksheet</em> will help your child identify the uppercase letter X and discover colors and shapes. Fun and effective, the similar <a href="/reading/alphabet/lowercase-letter-x-color-by-letter-worksheet">Lowercase Letter X Color-by-Letter Worksheet</a> is also available.