There is no reason for the leaders to be rainbow or whatever honestly.
The colored power rating is pure metagame thing we as the players see. It displayes the knights individual combat power and provess.
Thats not something a leader requires at all for ruling a nation.
Sure there have been kings who took to the battlefield and lead from the front, but the more we move forward in history the rarer they become.
For all we know, she can be weak AF but still hold true political and economical power due to being a smart ruler.
But yes, its nice to see characters who are supposedly important in the story also have the adequate rarity assigned to them. Not that its required though.
I am just happy another low tier girl got recycled to a higher tier, regardless the fact that its been a while since I saw a rainbow pot.