Cubism Crossword

It is multiple, here are the clues:

1. Cubism has often been likened to looking at something through a fractured.... (6 letters 3rd letter r last letter r)

2.When a work of art has different heights in it 6 letters 3rd word l)

3.When we make colours go gradually from dark to light or from one from another (8 letters last letter g)