Oh well... I want to say something on this topic, but I cannot. I don't know vocabulary enough for do it

. Bah I'll try it.
Colors are just frecuencies of the light. Mini_Mouse posted a picture where you can see the frecuencies that we can see. Just a really little zone. Some animals can see more. Snakes can see infrared light. Infrared light is sent from the hot objects. So snakes can see the things that are alive, because they send infrared light. Certain insects can see it to. Some flowers seems white, but when the insects see a picture on it, because they have "colours" on the infrared zone.
Other animals like bats uses sounds for "see". It don't gives information about colors but is better that eyes for know how far the things are from you.
Shadow_Paladin said that we see all the same color. Well, noone can know it, but think that it can be true. Our eyes are all the same, right, but think that when the color information goes on the nerves, it is just electricity and then our brain must recreate the colors. Our brains are not all the same, so why can it be impossible? You know that some colors make some people feel things like be happy, or be sad, and that it changes from one person to another. Is that because we are seeing diferent colors? Noone can answer that.
I think that be color-blind is not as bad as the people thinks because a color-blind never knew what some colors are. You cannot miss something until you know what it is. Think that it can be same as we. We cannot see infrared light. Are we missing it? Anyway it can be annoying.
About if dogs smells colors, no. Dogs don't smells colors, they see in black and white. But... think a little! If you see a black and white image you can know what is yellow, what is blue, etc. Because some are darker that others. So with a little of practice and knowing how many light is in the room you can know what color is.
About -black-death- posts I must say that we don't the same color if the colors that are around it are diferent :

Also they can look the same if you don't have another for compare. If you put that red the people could say that it is pink. If you put it togheter pink the people will say that it is red.
Also I want to say something more for do your guys think:
Think that your guys are walking into a 2 dimension world (cartoons). They will not be able to see the 3rd dimension but, does it exists? Now aply that to a 3rd dimension world. What happen if there is a 4th dimension that we cannot see? What happen if a section of our body that we cannot see/touch/smell/hear/etc exists in that dimension? What happen if telepathy exists? And if all we are connected in that 4th dimension. That let you think a lot.
Well, I think that this is all that I wanted to say =P