Odd tiff problem

i followed a tutorial about making business cards in photoshop. I used cmyk colours as instructed and also a resolution of 300. Everything looked fine as i created the card. The final instruction was to save the image as a tiff - i did this also.

ok, when i checked the tiff image in my picture viewer, the colours are different (although oddly, i like the result)

i am sening in a screen shot so you can see. Why is this colour different as as tiff?

thank you.