It’s hard to make the grain in mahogany ‘pop’. A dark grain filler will accentuate the pores but you can’t really do anything (that I know of) to heighten the grain lines. The darker the finish, the less the darkened pores show up. A light finish will show up more, but even so, with small pores it’s an effect that you’ll only really notice from quite close up.

You can go the ‘TV Yellow’ route by first applying a light cream or light yellow base coat, and then grain filling the pores on top of that, with clear coats over. That definitely highlights the pores, but hides the grain lines.