lavan

The color white in Hebrew is lavan לבן, and not surprisingly, we find many words that are directly related to this root:

• levana - לבנה - a poetic form of "moon", as appears in Yeshayahu 24:23, 30:26 and Shir HaShirim 6:10. Literally, "the white one".
• Levanon (Lebanon) - לבנון - named after the snow-capped, white mountain range
• leben - לבן In Arabic, laban means milk, and a form of coagulated sour milk (like yogurt) is called leben in Hebrew, and a cheese made from leben is called labaneh.
• levona - לבונה - frankincense. Klein writes that it is so called from its white color.
• livneh - לבנה - Styrax, birch. According to Klein, it literally means "the white tree", which is also the origin of "birch".
• the verbs ללבן and להלבין mean, in addition to "be white" or "make white", to make white hot (libun ליבון), to launder (also money laundering - halbanat hon הלבנת הון), to clarify, and to embarrass (להלבין פני חברו - literally "to make his face white").

One word with the root לבן that is not connected to "white" is levenah לבנה - brick. In fact, we find a brick of sapir (sapphire) in Shmot 24:10. From levenah we get the word malben מלבן - rectangle, from the shape of the brick, or the shape of the mold the brick was formed in (Nachum 3:14).
Steinberg does connect levenah and lavan, by saying that the root לבן means "to burn". This can lead to the creation of bricks on the one hand, and the color white on the other.
Rosenthal mentions levanim in Modern Israeli slang having the association of Ashkenazim, soldiers in the Navy, and (not in Rosenthal) undergarments. And if I'm already mentioning undergarments, here's a great story from a friend about mixing up the meaning of lavan:

For Chanukah, all the parents in my son's gan were asked to send "garbayim lebanot". My husband and I read the note he brought home and quickly realized that we didn't need to do anything - only the girls needed to bring a pair of socks. The next day at the gan I was reprimanded for not sending socks with my son to gan - Oh, I quickly realized, all the kids needed to bring in a pair of girl's socks. So I sent my son to gan with a pair of pretty pink socks with lace around the top. When I picked him up the next day, I was again reprimanded - "the socks have to be white so they glow in the dark - why did you send pink?" "Oh garbayim LEVANOT" How was I supposed to know?
I told the story to a friend of mine who is an ulpan teacher, whose son is in the same
gan and she said that it was a natural mistake - socks are masculine so they should have asked me to send "garbayim levanim". I'm not sure that this would necessarily have helped me - I would probably have sent a pair of blue tube socks the first day.