With a quality paint job, there's no reason to think your siding won't survive another 70 years (obviously with subsequent repainting).

My parents had their aluminum siding painted years ago and it held up very well.

Aluminum siding of that era was designed specifically to chalk off so that it gives the appearance of being clean. If the proper prep work & primer is used theres no reason it shouldnt last many years. A painter told me once its better than wood for holding paint, cos its not expanding/contracting or absorbing moisture. You might want to ask your painters what method specifically they would usse and run it by the people on the Painting forum Theres no reason you shoud have to get rid of perfecty good siding if the only probem is the color.

I can say our aluminum sided house was painted, in the 70s. It has shown the wear, only in the last 7 years. We have an old house, the new addition was added in 1898 ;^). We were worried about what is hiding under the siding. So, we have been gradually taking it down, insulating and residing.

I would definately paint yours if possible. Propperly primed and finish coated I feel like it will last 20 plus years. I did test patches on this house 7 years ago, it looks like I just did it :^)