Converting Grayscale To RGB

I am trying to add some B&W photos that I scanned. In a previous post I was advised to convert any grayscale pix to RGB. Is there a way to convert using os x 10.3.9? I think I figured it out in photoshop. When I open the pic in preview and select "get info" the profile reads "sRGB IEC61966-2.1". Is that ok? Someone please help lol. Thanks in advance.