Answer: If the clothes have been dried, the dye has been driven into the fabric which makes it near impossible to remove – considering the pants are colored. Red is considered a loose dye, and will bleed out of fabrics regardless of the age of the clothing. I would suggest that you try soaking the pants overnight in a solution of detergent and oxygen bleach (sodium perborate). This could pull the red splotches – most likely only a 50/50 chance of success though.