I don't think "Negro" is an acceptable term anywhere today. The usual terminology is "black," unless you're in the United States, where it's preferable to say "African-American."
If someone has dark or tanned skin, you can either describe them as "dark skinned" or refer to them as "dark complected" or "she has a dark complexion." If they are black, they can be described as a "dark-skinned black" or "light-skinned black." Caucasian people are described as "white." "Pale" is usually only used to describe a complexion if the person is sickly or unwell.
"I'm a light-skinned black woman, what shade of lipstick would you recommend for me?"
"My best friend is of Italian descent, but with her dark complexion she often gets mistaken for Mexican or Iranian."
"You'd better get out of this hot sun - with your fair skin, you'll burn to a crisp!"
"He wouldn't admit that he was frightened, but his face was very pale after he got off of that roller coaster."
(NOTE: If you want to be very technical, in the U.S., the Equal Employment Opportunity Commission classifies "white" as non-Hispanic or Latino, non-black, non-Asian, non-Alaska native or American Indian, non-Hawaiian, and non-Pacific Islander.)
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