As described in #129974, the colorpicker cannot cache a promise protected by `useService`. #129974 fixes the issue by through non idiomatic practice (calling a service that is not protected by `useService`). This commit fixes the issue idiomatically. This commit caches the promise directly from a service and removes the caching code from the `ColorPalette`. task-3446691 closes odoo/odoo#130789 X-original-commit: 1d2e54088b0f0e28464ab6aa884fb2e1110e8e04 Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>