I have a couple of older Ruger 4" stainless .357s myself..I simply carefully painted the rear edge of the front blade sights with orange da-glo model paint...hafta touch it up from time to time tho.
You can also help things by painting the rear edge of the REAR sites with FLAT BLACK model paint...simple and cheap. Works for me.

I love my older Rugers..they were police trade-ins 20 yrs ago and shoot fine.