Aaronic Priesthood Manual wrote:Quotation and discussion
Compare the results of the vote with the following statement by President Spencer W. Kimball. Have a young man read it.
“We recommend that people marry those who are of the same racial background generally, and of somewhat the same economic and social and educational background (some of those are not an absolute necessity, but preferred), and above all, the same religious background, without question” (“Marriage and Divorce,” in 1976 Devotional Speeches of the Year [Provo: Brigham Young University Press, 1977], p. 144).
• Why is it so important for a couple to be worthy members of the Church? Ensure that the following points are discussed:
1. Exaltation cannot be attained without celestial marriage.
2. Religious values are powerful, and conflicting values can cause continual stress.
3. President Kimball quoted a survey showing that “only about one out of seven non-member spouses would be converted and baptized into the Church” (“Marriage and Divorce,” p. 152).
4. When one spouse is not converted to the gospel, the children are caught between the differing values of the parents.
• Why is it important for a couple to have a similar economic, educational, and cultural background?
Bold emphasis mine. "Recommend" is different from "command". This means, it's a good idea...not a "make or break" deal.
Also, let's evaluate the last question for a moment.
Why is it important for a couple to have similar economic, educational, and cultural background?
I agree that the more things you have in common, the greater chance there is that you, as a couple, will be able to relate to each other on common ground.
Now, this can be done, even if cultural and economic backgrounds are different...but it is more difficult.
I really think that is all they were trying to say here.
It still does not stipulate that you can't marry someone of a different race. The brethren simply have no ground to stand on if they do that now that the priesthood ban has been lifted.