My Mom's Valentines Day Card: Colorblindness or Alzheimers?

I know Valentines Day was last month, however, I only received a sweet card (shown) from my mom last weekend. Seems the postal service delivered my card to the wrong address, and then it was sent back to my mom, who finally hand-delivered it to me this past weekend when I visited. And she had the correct address, so looks like the mail carrier can't read, but whatever.

My mom is so sweet to still give me cards when I'm 42 years old. The message was basically, "I sometimes wish you could be a kid again, but I'm so proud of the adult you've become." Awwwww, thanks, mom! But the odd part was what was on the card, and this is where my concern comes in because I'm not quite sure how to take it.

Like most cards, this one had generic images of 2 kids and an adult, except--they're black! All of them. Clearly, this is a card marketed for black families. Now, I wasn't offended by any means; I just found it strange. And when I said something to my mom and pointed out the pictures, she gazed at the card and just laughed as if to say, "Oh well, silly me!" Again, sweet card, sweet mom--and gosh darn it, I thought, she doesn't even SEE race! Wow. If only we all lived in a world like that. And how lucky am I to have a mom that doesn't even notice skin color!

Except I wonder if there's more to it. She'll be 72 this year. My sister has confided in me that our mom is starting to forget things and drop random bits into conversations. Plus, I have 1 uncle and 1 aunt who already have Alzheimers! I'm not sure how to take it. I don't want to press too much and make her self-conscious and sound ungrateful, but I also don't want to ignore clear warning signs that something's wrong. Colorblind or Alzheimers--which do you think it is?