Since [1], the colorpalette widget's layout was updated such that some colors now appear multiple times in some circumstances (e.g. the grays appears in custom tab and theme tab). Since then, asking to mark one of those color as selected, only marked the first one as such, and that first one may be in an hidden panel. This commit fixes the issues by marking them all as selected, as it should. This changes what is explained in [2] too. [1]: https://github.com/odoo/odoo/commit/96ab729850983162a0039e40c77537ef65cd039e [2]: https://github.com/odoo/odoo/commit/508a7f980652172a7ed00da43f6bc3bc586089fe Part of https://github.com/odoo/odoo/pull/73611 task-2599770