I know you can buy suede dye for shoes, but I have a feeling that it would all end up on your jodhs..... Maybe ask a dry cleaners that does re-dyeing for advice?
I recently bought a show saddle from the Native Pony Saddle company...suede seat and knee and thigh bits. Lady who cam and fitted it for me from the Native Pony saddle Co. said she uses 1001 carpet cleaner to revive the suede. If its gone smooth and shiny, you could try using course sand paper to lift the fibres, but start off gently.