They may be able to see better in the dark but even then they seem to rely on their sense of smell or "follow their noses" much more. Their sense of smell is very acute and they have been known to be able to smell grubs, bugs, and worms under twelve inches of soil and then dig up the tasty morsel. I don't have any raw data or published reports but most things I have read lead me to believe they rely on their eyesight very little.
I don't know if they are colour blind or not. I've heard of many hedgehogs that won't use certain colours of hedgie bags. For my gangs first Christmas I made them all Christmas hedgie bags. Smokey's had a red lining. He would not go in it and Smokey loved bags. I switched his with one of the others with a different colour lining and he rushed right in. No way would he go in that red bag until I picked him up and put him in it. After that he was ok with the red bag. It wasn't that the bag was new, they were all new so it had to be the red lining. :?
I've heard of hedgehogs rejecting toys of one color while accepting otherwise-identical ones that are a different color. I've also seen people discuss what their hedgehogs' favorite colors are--it always seems to be bright ones. Hedgehogs apparently prefer colors like red, yellow, and blue--not dusty rose, mustard, and smoke. It's possible that they see color, but not very subtle variations of it. When you think about it, bright colors tend to have important meanings in the wild, like, "Hey! I'm tasty! Come pollinate me!!" or "I'm extremely poisonous! Go away!!" Perhaps that's why some hedgehogs have strong reactions to certain colors.
Just my .02 hypothesis.
That said--I've never had a hedgehog who cared what the color of anything was. The question is more like, "Can I eat it?! If not--can I nose my way under it, and will it be dark when I get there?!"
Curiosity was killing the cat, so I ran a GOOGLE search. I found many responses that referrenced a hedgehogs eyesight: "They have a strong sense of smell and hearing, but relatively poor eyesight."
"Hedgehogs have poor eyesight. They use smell as their primary sense. Your hedgie will learn to identify you by smell. The best way to do this is to spend time with your pet several times a day just gently holding it to allow it to adjust to you and learn to recognize your scent." http://www.exoticpetvet.com/breeds/hedgehog.htm
As far as color blind, I found nothing that showed anyone knew the answer to this question. I had to search through many sites, and apparantly there has been some testing, but nothing conclusive with the results. Very little out there about this issue.
I was wondering the same thing! The other day I was having play time and treat time with luna on the kitchen floor, and when I feed her bug treats I always hold it above her head so she looks up and takes it gently and more hesitantly rather than attacking the tweezers at ground level (I'm scared the tweezers might hurt her little mouth or damage her teeth). She didnt seem to see the bug if I put it on either side of her head, just infront of her ears. I thought I was showing her the bug, but she didnt seem to see it at all and sniffed the air. I'm glad I read this though!! I was worried my baby girl might have had a problem! Weph!