Complex sentence: The symbol was a diamond with sides of five centimeters; the border, about half a centimeter, and the letter P (two and half centimeters tall) were violet, while the inside of the symbol was yellow.
Split into simpler sentences: The symbol was a diamond with sides of five centimeters. The border (about half a centimetre mide) and the letter P (two and a half centimetres tall) were violet, while the inside of the symbol was yellow.