Mine is Titan color and you are right it is little darker for your interior. Would you consider this instead? http://www.ecstuning.com/BMW-E90-325...Trim/ES117049/
It is not dark as mine in terms of color and brushed aluminum goes wonderful with everything as you know.
Quality wise they are very solid and even mine looks like metal. If I were you I would get a aluminum vinyl sample from a signage shop and see how it looks.
It is up to you. Don't let your ideas die.