You should not use teams always rainbow. Basically for defense raid best is using rainbow.
But for offense I always use stack color 3-1-1, or 3-2 or 4-1 or 5-0, so example for 3 green, 1red (because heal+att) and 1purple (because mana control), so just like my post above team 3 (with 3 green heroes). This is just an example.
So for your case, maybe like this for offense:
Opponent tank is yellow, so we bring:
Kage, Proteus, Rigard, Caedmon, Hansel.
Opponent tank is blue, so we bring:
Melendor, Caedmon, Hansel, Proteus, Kiril/Boldtusk
IMO, I suggest build 2-3 rainbow teams *4 maxed, before starting *5 heroes, because *4 4.70 is stronger then *5 3.70 (with the same resource mats). So while waiting resources, we already have strong base *4 heroes to get resource from farming Atlantis, Event challange (*4 heroes can used for both Epic and Legendary limit), Season, Titan, Raid.
Notes: IMO, this is only my suggestion, you actually should not ascend Lianna over Melendor, and also not ascend Isarnia over Kiril. Kiril and Melendor help alot for our tools support.
And also you should ascend Proteus and Rigard 1st over Sehsat.