I just dyed my old (first) pair of BMW City riding pants and now they look almost as good as when I first purchased them.
Originally a charcoal colour they faded to a pale grey which did not look good but otherwise they still were in excellent condition. I purchased some charcoal fabric dye from eBay cheap and 30 minutes of soaking in hot water with the dye gave me an excellent result. The photo perhaps does not do justice but the dye process has restored the colour to a dark and even level again.
Just posting this as an idea for others to consider with their riding jeans due to the high replacement cost. I think you need to be mindful of the condition of any Kevlar liner before considering as that deteriorates but otherwise perhaps a cheap way to extend or bring a favourite back to life even if just to keep as a spare. These BMW pants use different method of protection to Kevlar so were not reduced in strength and will now see active use again.