Welcome, my name is XXXXX XXXXX I will do my best to help you with your issueYes you can paint aluminum siding. The paint will last as long as a coat of paint on any wood siding maybe longer.
You can use warmer colors. Paint sample strips typically have compatible color choices
Even tho, the newly painted siding is washed with household product?
I don't understand your question. If you mean will the new paint be washable then yes exterior paints are washable
My concern is that the new paint color will begin to fade from washing?
Not from washing but if you paint a dark color it can fade from the sun. but usually the side of the house that faces the sun will fade uniformly so you won't really notice. The color will fade even with aluminum siding with the original paint