How to write a Spring Data JPA specification for a Postgres select from function?

I have a table with a JSONB column in Postgres. Let's call it pet.

I'm trying to come up with a Spring Data JPA specification that can filter the records of this table based on the attributes of the details column. However, I need to be able to filter by attributes ending with Colour, not the exact attribute name. I was able to achieve this by using a Postgres query such as this one:

select * from pet 
where exists (
    select from jsonb_each_text(details) as kv 
    where kv.key like '%Colour' 
    and kv.value = 'red');

I'm finding it extremely challenging to come up with a JPA specification for the above where clause. I have tried this:

(root, criteria, builder) -> {
    Expression<Tuple> function = 
        builder.function("jsonb_each_text", Tuple.class, root.get("details"));
            
    // Not sure how to set alias or if it's even 
    // necessary as in my SQL
    var kv = function.alias("kv");

    var subQuery = builder.createQuery().subquery(Tuple.class).select(function);

    // I'm unable to work out how to determine this root. 
    // I cannot use Tuple as a root as it's obviously not 
    // an entity and thus I get an appropriate error.
    var functionRoot = criteria.from(Tuple.class); 

    return builder.exists(subQuery.where(builder.like(functionRoot.get("key"), "%Colour"), builder.equal(functionRoot.get("value"), "red")));
};

My Pet entity class looks like this:

import com.vladmihalcea.hibernate.type.json.JsonType;
import lombok.Getter;
import lombok.Setter;
import org.hibernate.annotations.Type;
import org.hibernate.annotations.TypeDef;

import javax.persistence.Column;
import javax.persistence.Entity;

// Other imports skipped for brevity

@Getter
@Setter
@Entity
@TypeDef(name = "json", typeClass = JsonType.class)
public class Pet {

    @Id
    @GeneratedValue
    private UUID id;

    private String name;

    @Type(type = "json")
    @Column(columnDefinition = "jsonb")
    private Map<String, Object> details = Collections.emptyMap();

}

What am I doing wrong here?

Any tips, pointers, guidance here would be greatly appreciated.