He just added Acetic Acid until it became clear.
Cuz it was yellow and appealing! Sorry if this is bad. Seen too many of the same jokes here and I wanted to add an original joke.
Because they all add up!
Pho Kyuu EDIT: No one understands how to pronounce "Pho". ;;
because lions only understand .rars
Chemistry, because there is lots of acid involved.
I dunno, but I'll go down in math and chemistry too.
Me: (with a mouthful of salad topped with vinaigrette) I dunno.