I tried /summon minecraft:axolotl ~ ~1 ~

{Variant:"1"}

and it did not give the right variant, I got a pink one.
I then got the data from a random one with the same variant and did /data get entity 9bf31f29-85b3-40ac-9981-0168b5feca1a

I then summoned it with the info from data get
/summon minecraft:axolotl ~ ~1 ~ {Brain: {memories: {}}, HurtByTimestamp: 0, Attributes: [{Base: 16.0d, Modifiers: [

{Amount: -0.09020662722619766d, Operation: 1, Name: "Random spawn bonus"}

], Name: "minecraft:generic.follow_range"},{Base: 1.0d, Name: "minecraft:generic.movement_speed"}], Invulnerable: 0b, FallFlying: 0b, ForcedAge: 0, PortalCooldown: 0, AbsorptionAmount: 0.0f, FallDistance: 0.0f, InLove: 0, DeathTime: 0s, HandDropChances: [0.085f, 0.085f], PersistenceRequired: 0b, Age: 0, Motion: [-0.002995948136713688d, -0.0784000015258789d, 2.8869604154189917E-4d], FromBucket: 0b, Health: 14.0f, LeftHanded: 0b, Air: 5774s, OnGround: 1b, Rotation: [84.49826f, 24.352903f], HandItems: [{}, {}], Variant: 1, ArmorDropChances: [0.085f, 0.085f, 0.085f, 0.085f], Pos: [26.509281634764015d, 65.0d, 69.21015484485108d], Fire: -1s, ArmorItems: [{}, {}, {}, {}], CanPickUpLoot: 0b, HurtTime: 0s}