There's not much to go on here. Your dad would be about 75-85 years old (assuming he was between 21 and 31 in 1957).
Have you petitioned to see your adoption records? That should be your next task.
Any photo already on the Internet can be posted here.
Go the page containing the photo.
Right click on the photo.
Click on Properties.
Select and Copy the url address.
Looks like http://i1.nyt.com/images/2011/01/13/world/13SHANGHAI1/13SHANGHAI1-thumbStandard-v2.jpg
Open a post in a2k.
Click on Img at the top of the box.
Paste the url address IN BETWEEN the two [img] [/img].
Preview it to make sure it worked.
What makes you think you are mulatto? Have you had a DNA test?
Most of the people in the world have darker skins than Danes or Germans. You could be Persian or Indian or Hispanic or .., the list goes on.
Good luck, kiddo.
Joe(I really hope you find some trace)Nation