I think the difficulty you’re going to run into is trying to do that in blue. Cermark is the laser marking stuff you need, but it marks in jet black. The blue they make isn’t at all that nice deep blue in the thin blue line symbol you’re referring to, and their blue is specifically for glass.
One thing I thought of you might try is to get someone with a CNC machine to carve a space for that symbol into each grip, either in the middle or down toward the bottom, and use the GF to make an acrylic inlay of bright blue to embed there. If something goes wrong, all it costs to fix is the price of a new grip. I wouldn’t try anything like that on the frame or lower receiver, because that’s where the serial number is. Obliterating those definitely bad juju.