Can I consider this as two separate groups of 12 teams? So if 12 teams in a group are the letters A to L, they could play as follows:
Green A - Day 1
R1 R2 R3 R4 R5 R6
game1 (J B) (C H) (L K) (G A) (D I) (F E)
game2 (C A) (L E) (J I) (F B) (G K) (D H)
game3 (F L) (D J) (G C) (E K) (A H) (I B)
Green B - Day 2
R1 R2 R3 R4 R5 R6
game4 (G E) (F I) (D A) (J H) (L B) (C K)
game5 (H I) (K A) (B E) (C D) (J F) (L G)
game6 (D K) (G B) (F H) (L I) (C E) (J A)
The same schedule could be used for the other group of 12, only it is played on Green B on Day1 and then Green A on Day 2.
