This cube is for the sol purpose to use my collection in its entirety.
Few rules override:
The prismatic Piper can be partnered with any commander
Split cards can be treated as only 1 of the colors in its cost
Planeswalkers can be commanders
Double Faced cards have color identity of the front half (see Brutal Cathar)
Creature that produce mana have the color identity of its casting cost (See noble hierarch)
If a card has an ability which required the payment of another color from its casting cost, its identity is both those colors (see Alesha who smiles at death)
Your sideboard is the additional cards drafted (See 'Karn, The Great Creator')