One powder is grassy, the other fruity - one green like the grass, the other orange like the sun. Jalapeño and aji amarillo powders are delicious foils to one another. While they have certain differences, there's a brightness to both of these chilies that tie them together very well.
Jalapeño powder: Grassy and bright (see PepperScale's profile)
Aji amarillo powder: Fruity and bright (see PepperScale's profile)