I can confirm that the split predates X2.
Light green (111,189,72) was used to indicate Savoy/Piedmont/Sardinia (it was all one kingdom for a long time) by TACOS, GCS, ARCS, RCS, MCS, and CCS. A darker green (0,146,70) was used by GCS for a unified Italy.
The rusty brown (153,51,0) was used...