Business and Professions Code § 13536

13536.

All letters, words, figures, or numerals which are part of the advertising media referred to in this article shall have a heavy type face or stroke, shall be clearly visible, and of a color or tint that will contrast the letters, words, figures, or numerals with the background of the advertising media. The height of the letters, figures, and numerals, except the letter “l” and numeral one, shall not be more than twice the width.