Lines connect two points and can be used to help define shapes, make divisions, and create textures. All lines, if they’re straight, have a length, width, and direction.
Shapes are self-contained areas. To define the area, the graphic artist uses lines, differences in value, color, and/or texture. Every object is composed of shapes.
Color palette choices and combinations are used to differentiate items, create depth, add emphasis, and/or help organize information. Color theory examines how various choices psychologically impact users.