Custom validation using Joi in Javascript

I'm using Joi to validate some data from user.

I want to compare between two keys (type: array) in the payload and validate that one should be the subset of the other.

for example:

{
    "colors":["green", "blue"],
    "animals":["cat"],
    "branches":[{
       "colors":["green", "red"]
    }]
}

In above example i want to make sure that first array (colors) is superset of second array inside key branches (colors).

this could be achive by following code in js, but i want to do it using Joi.

const result1 = req.body.branches.colors.every(val => req.body.colors.includes(val));

Any help?