Lava is a nice alternative to bark and will maintain its color indefinitely. Locally mined lava is available in Red, Black, and Red/Black mix. Lava is available in 3/8" minus or 1" sizes.
Lava Fines. (red, black and mixed). $37.50 per cubic yard.
1" Mixed lava. $49.50 per cubic yard.
1" Red or Black lava. $54.50 per cubic yard.