That is a pretty liberal definition of multiple phases, looks like assuming a 50/50 mix, only ~10% of the bulk mass would be the Ga (can I read a phase diagram like that? I am a bit rusty on my solid state chem) and try telling them apart by appearance....
I wonder if a ternary metal mix would be the sexiest result? Say Au/Hg/Ga. I know Hg is used to extract Au from stuff, and Au should be more soluble in Hg than Ga, so the result may be the "salting out" of the Ga from the Au/Hg layer much like some solvents can be salted out of aqueous solution with salts. And with any luck, with enough gold the Hg/Ag layer will be goldy colored compared to the silver of Ga making for a nice visual. I'll let you check phase diagrams to see if there is any truth in this idea or if I am just talking out my ass.