Colorful Patron

You always had an aptitude for colors and the powers that they hide so it was not a surprise when the God of Colors made a pact with you. You would do his bidding and he would give you powers over colors and the magic tied to them.
Playtesting required, changes will be implemented after this, suggestions are welcome.

Color Mastery

At 1st level you can choose 2 colors which are associated with a damage type as follows:
Orange - Acid
Blue - Cold
Red - Fire
Yellow - Lightning
Green - Poison
Grey - Thunder
Black - Necrotic
White - Radiant
Additionally, the 2 selected colors grant effects when you cast a spell (even cantrips) with the associated damage type (?or an effect which has the same color?). Also, you receive a Cloak of Shifting Colors from your Patron to which your colorful magic powers are tied to. When you deal damage of one of your chosen damage types your Cloak of Shifting Colors bursts alight with the color associated with the damage type for 1 minute and when you deal damage of another of your chosen damage type with a spell your Cloak of Shifting Colors automatically changes to that damage type's color. On spells that deal more types of damage that cause this effect you can decide which color your Cloak of Shifting Colors becomes. While your Cloak of Shifting Colors is active with one of your chosen Color Mastery you gain extra effects as described below.

 

Black Color Mastery

Associated damage type: Necrotic
Effect: Whenever you deal necrotic damage with a spell your Cloak of Shifting Colors turns pitch black for up to 1 minute or until you cast a spell with your other chosen color's associated damage type. 
While your Cloak of Shifting Colors is black you can turn invisible in darkness or dim light if you are not moving.
As a bonus action while your Cloak of Shifting Colors is black in color you can use the darkness and necrotic energy to pull the lifeforce out of someone by touching them for your warlock lvl  + your Charisma modifier necrotic damage and healing you for half as much (rounded down).

Blue Color Mastery

Associated damage type: Cold
Effect: Whenever you deal cold damage with a spell your Cloak of Shifting Colors turns a blue color, and small spikes of ice form on it for up to 1 minute or until you cast a spell with your other chosen color's associated damage type. 
While your Cloak of Shifting Colors is blue in color melee attackers that hit you receive your warlock lvl  + your Charisma modifier cold damage.
As a bonus action while your Cloak of Shifting Colors is blue you can create an icy shell around your body granting you your warlock lvl  + your Charisma modifier temporary hitpoints until the end of your next turn.

Green Color Mastery

Associated damage type: Poison
Effect: Whenever you deal poison damage with a spell your Cloak of Shifting Colors turns a green color,  and small vines sprout from it for up to 1 minute or until you cast a spell with your other chosen color's associated damage type. 
While your Cloak of Shifting Colors is green in color you have advantage on saving throws against Poisoned condition.
As a bonus action while your Cloak of Shifting Colors is green the vines on your cloak surge toward a medium or smaller creature up to 30ft, that you can see and who stands on the ground, who makes a Dexterity saving throw if failed they lose half of their movement on their next turn.

Grey Color Mastery

Associated damage type: Thunder
Effect: Whenever you deal thunder damage with a spell your Cloak of Shifting Colors turns an opaque grey color,  and tufts of fog start to seep from it for up to 1 minute or until you cast a spell with your other chosen color's associated damage type. 
While your Cloak of Shifting Colors is grey in color you have +1 AC against ranged attacks and ranged spell attacks.
As a bonus action while your Cloak of Shifting Colors is grey the tufts of fog that seep from your cloak coalesce into a sphere fog cloud 5ft in radius around you until the start of your next turn and anything inside of this cloud is heavily obscured from the outside and ranged attacks against creatures inside this fog have disadvantage, this fog does not make you automatically succeed in hiding but makes it easier. You can not make this cloud if there is a wind faster than 20 miles per hour.

Orange Color Mastery

Associated damage type: Acid
Effect: Whenever you deal acid damage with a spell your Cloak of Shifting Colors turns a sickly orange color for up to 1 minute or until you cast a spell with your other chosen color's associated damage type.
While your Cloak of Shifting Colors is orange in color you have a +1 on ranged attack and ranged spell attack rolls.
As a bonus action while your Cloak of Shifting Colors is orange you can enhance your next ranged spell or ranged attack to deal your warlock lvl  + your Charisma modifier extra acid damage until the end of your next turn this damage does not refresh the timer on your orange color.

Red Color Mastery

Associated damage type: Fire
Effect: Whenever you deal fire damage with a spell your Cloak of Shifting Colors turns a bright red color, and seems as if embers are burning on the inside of it for up to 1 minute or until you cast a spell with your other chosen color's associated damage type. 
While your Cloak of Shifting Colors is red in color it acts as a source of weak light for a 10 ft radius and as a source of warmth and fire.
As a bonus action while your Cloak of Shifting Colors is red you can create a fiery burst around you dealing your warlock lvl  + your Charisma modifier fire to damage to everyone, including you, in a 5 ft radius.

White Color Mastery

Associated damage type: Radiant
Effect: When casting a spell with radiant damage your Cloak of Shifting Colors turns a brilliant white color burning with an inner radiant light for up to 1 minute or until you cast a spell with your other chosen color's associated damage type. 
While your Cloak of Shifting Colors is white it acts as a strong light source for a 30 ft radius and dim light for another 30ft.
As a bonus action while your Cloak of Shifting Colors is white in color you can create a radiant burst of light which makes everyone do a Constitution saving throw in a 5ft radius if failed they lose their reaction.

Yellow Color Mastery

Associated damage type: Lightning
Effect: Whenever you deal lightning damage with a spell your Cloak of Shifting Colors turns a yellow color, and small surges of electricity run up and down it for up to 1 minute or until you cast a spell with your other chosen color's associated damage type. 
While your Cloak of Shifting Colors is yellow in color your speed is increased by 10ft.
As a bonus action while your Cloak of Shifting Colors is yellow you can send the surges through your body making your actions faster enabling you to make an attack.

Colorful magics

Your pact and your natural aptitude for colors lets you learn any spells of the appropriate level which has a colorful efect or has a damage type of one of your color masteries. The DM can decide to not allow you to learn certain spells.

Additional Color Mastery

Starting at 6th level, your patron satisfied with your strength grants you an additional color mastery.

Color Resistance

Starting at 10th level you have resistance against damage type(s) that are currently associated with your Cloak of Shifting Color's color.

Color Duality

Starting at level 14 you can have 2 colors active at the same time intertwining their effects. This means you have both of their passive effects and you can use both color's active effects. Also, you gain extra once per long rest effects for each of your mastered colors.

Black Ascension

Associated damage type: Necrotic
Once per long rest, while your Cloak of Shifting Colors is black as an action you can cast Blight at lvl 4 without using a spell slot.

Blue Ascension

Associated damage type: Cold
Once per long rest, while your Cloak of Shifting Colors is blue as an action you can summon an icy armor around you, which grants you 5d10 temporary hitpoints for 10 minutes. You also gain +2AC until you have the temporary hitpoints from this effect.

Green Ascension

Associated damage type: Poison
Once per long rest, while your Cloak of Shifting Colors is green as an action you can summon an Earth Elemental with the same rules as in Conjure Elemental spell except that the duration is 1 minute, there is no material requirement and it requires no concentration so it can't turn hostile against you.

Grey Ascension

Associated damage type: Thunder
Once per long rest, while your Cloak of Shifting Colors is grey as an action you can let out a thunderous roar. Each creature of your choice that is within 30 feet of you and can hear you must succeed on a Wisdom saving throw or be frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Orange Ascension

Associated damage type: Acid
Once per long rest, while your Cloak of Shifting Colors is orange as an action you can summon 5 arrows, for 1 minute, that are considered magical in nature, deal an extra 1d6 acid damage and on hit decrease the target's AC by 1.

Red Ascension

Associated damage type: Fire
Once per long rest, while your Cloak of Shifting Colors is red as an action you can enhance your melee weapon with flames granting you an extra attack with it if you used your action to attack this turn and makes it deal an extra 2d4 fire damage for 1 minute.

White Ascension

Associated damage type: Radiant
Once per long rest, while your Cloak of Shifting Colors is white as an action you can create a burst of holy energy around you in a 15ft radius which heals all living beings around you, including you, for your warlock lvl + your Charisma modifier and deals the same amount of radiant damage to undead creatures.

Yellow Ascension

Associated damage type: Lightning
Once per long rest, while your Cloak of Shifting Colors is yellow as an action you can enhance yourself with lightning speed increasing your movement speed by 20ft and now you don't provoke opportunity attacks for 1 minute.