It was narrated that Anas said:
"The Messenger of Allah (ﷺ) said: 'The man's water is thick and white, and the woman's water is thin and yellow. Whichever of them comes first, the child will resemble (that parent).'" (DE)
English reference (DE): Vol. 1, Book 1, Hadith 200 (DE)
Arabic reference (DE): Book 1, Hadith 201 (DE)