There's no doubting the visual appeal of the flamed maple on these Kala ukuleles. But the major contributor the the tone is the spruce top of the uke (giving it an immediate, mandolin-like sound).
Theguitarjunky does a demo with his Kala Flame Maple KA-FMC Ukulele.
Kala Flame/Spalted Maple Concert Ukulele - $219.99
Construction: Solid Spruce top, Spalted Flame Maple back and sides
Tuners: Chrome die-cast sealed geared tuners with amber buttons