How to tint the specular map in Unity5

i was wondering how can i change the STANDARD SPECULAR(setup) shader to allow me "tint" the specular map, because i have a complex .psd file(30mb) for a metallic material (an iron robot) and i want also a golden robot, copper robot, etc...and i think is a waste of space making ten or more specular maps with different colors in photoshop(200mb or more) and it will be a lot more easy just to use a desaturated specular map and tint it in the material, multiplying the "specular color" with the specular map...or how can i just mimic the standar PBL shader but with a specular color, and a glossines slider which will not dissapear when i add a specular map, insted of choose one of them, multiply them, can we do this, right? i have 0 knowledge of shader scripting, so im wandering if someone could help me, or just point me in the right direction :( ( please dont tell me that i need to write my own PBL shader,that is beyond my limits). THAnk YOU!