Summoning a horse that has dyed horse armor [duplicate]

This is my current command:

/summon horse ~ ~3 ~4 {Tame:1, SaddleItem:{id:saddle,Count:1}, ArmorItem:{id:leather_horse_armor,display:{color:3949738},Count:1}}

What's wrong with it?

I summoned a horse and put blue leather horse armor on it. I then looked at it and pressed F3+I and got this command copied into my clipboard:

/summon minecraft:horse 7.86 63.00 -142.70 {Brain: {memories: {}}, HurtByTimestamp: 0, Tame: 1b, Attributes: [{Base: 26.0d, Name: "generic.maxHealth"}, {Base: 0.0d, Name: "generic.knockbackResistance"}, {Base: 0.3144634919109718d, Name: "generic.movementSpeed"}, {Base: 0.0d, Modifiers: [], Name: "generic.armor"}, {Base: 0.0d, Name: "generic.armorToughness"}, {Base: 16.0d, Modifiers: [{UUIDMost: 7011061429969178561L, UUIDLeast: -6231576989739238927L, Amount: -0.012178698746547666d, Operation: 1, Name: "Random spawn bonus"}], Name: "generic.followRange"}, {Base: 0.0d, Name: "generic.attackKnockback"}, {Base: 0.7635032052473723d, Name: "horse.jumpStrength"}], Invulnerable: 0b, FallFlying: 0b, ForcedAge: 0, PortalCooldown: 0, AbsorptionAmount: 0.0f, Bred: 0b, FallDistance: 0.0f, ArmorItem: {id: "minecraft:leather_horse_armor", Count: 1b, tag: {display: {color: 3949738}}}, InLove: 0, EatingHaystack: 0b, DeathTime: 0s, HandDropChances: [0.085f, 0.085f], PersistenceRequired: 0b, Age: 0, Motion: [0.0d, -0.0784000015258789d, 0.0d], Health: 26.0f, LeftHanded: 0b, Air: 300s, OnGround: 1b, Rotation: [90.44398f, -3.7093549f], HandItems: [{}, {}], Variant: 773, ArmorDropChances: [0.085f, 0.085f, 0.0f, 0.085f], OwnerUUID: <my UUID>, Fire: -1s, ArmorItems: [{}, {}, {id: "minecraft:leather_horse_armor", Count: 1b, tag: {display: {color: 3949738}}}, {}], Temper: 15, CanPickUpLoot: 0b, SaddleItem: {id: "minecraft:saddle", Count: 1b}, HurtTime: 0s}

After cleaning the command up a bit, you get this command:

/summon horse ~ ~ ~ {ArmorItem:{id:leather_horse_armor,Count:1,tag:{display:{color:3949738}}}}

Executing this command summons a tamed horse with a saddle and blue leather horse armor.