Model 586-1

The dash 1 means it was the first change to that model.

You could have the front ramp insert removed and a different color one put in, but it's not not a quick, interchangeable swap like you think.

The dash number is an engineering change for that model. You can order different color inserts for the front sight at Brownell's or you can find a hunk of plastic and make your own.

To find info about your gun: If you have $40 bucks your not using, go to one of the big bookstores and pick up a copy of Jim Supica's "Standard Catalog of Smith and Wesson, Third eidition". That is the most valuable reference to all questions Smith related that I have ever seen.

The rear sight blade can be changed as well, taller etc. That requires a little more effort. Most times it's a matter of cranking the widage screw to the point it breaks. You then have to replace the screw/nut as well. (a gunsmith can do this in a matter of minutes.)

Brownell's is a good source of parts but there are many sources on the web.