I've noticed something quite interesting about the murals depicting the Diamonds. Yellow and Blue both seem to be holding and watching a series of circles. Pink is holding up a single one, which has a smaller one above it. I believe these are depictions of their colonies, seeing as the single one Pink is holding up could be interpreted as the Earth and its moon.
This would mean that Yellow has about 19 Gem Colonies, including the circles around the starbursts in her hands (which themselves could be stars), Blue has 9 Gem Colonies, Pink had 1 (Earth), and White has at least 5, maybe 6 if you include the orb she is holding.
Wait a minute, White Diamond, the gem we all asumed was the big boss and all that... has the least amount of colonies?! (Exculding PD cuz she's dead.) And Yellow, an army comander type person, has 19!?