Color symbolism is the use of color as a representation or meaning of something that is usually specific to a particular culture or society. Context, culture and time are certainly important factors to consider when thinking about color symbolism.
Definition of backpack for English Language Learners. : a bag for carrying things that has two shoulder straps and is carried on the back.
Bags are designed to carry everything from school books to mountaineering gear, or they may simply be a stylish fashion accessory carrying little more than the weight of a lipstick.