Why did his pads change colors??

Hi,
I have three kitties, one is 2yrs, one's turning 10 next month and my oldest just celebrated his 21st birthday . The oldest one's health has been going downhill the past couple of months, but he's in good spirits and I will continue to baby him, doing whatever is necessary (I watched him come into to this world when I was four, he is my baby). I just noticed that recently his paw pads changed color and I have no idea why. He used to have all solid black paw pads, like a gorilla and now they are pale pink with some small spots of brown.
Does anyone know why this sudden change would happen, it's like he lost his pigmentation or something? Please let me know if this is normal or if this is yet another worry I can add to my list.

~S

In any cat and especially a senior citizen ( Wow 21 - god bless him) a change in the norm needs to be addressed by a vet. You did say he has been not feeling his regular self. Changes is the coloration of the paw pads could mean he is possible laking Minerals, Nutrition due to (?) if they are cold they possibly are not get the circulation they need -
there are so many reasons why and only by taking him to a Vet for a thorough check -up and a Senior Blood Panel would he be able to tell you the best course of treatment if any is needed.

All the best to you and you baby!!