There must be a Unicode geek here who can explain why the heart emojis include grey, pink, and light blue variants, but the circles and squares don’t?

⬛⚫🖤
🩶
⬜⚪🤍
🩷
🟥🔴❤️
🟧🟠🧡
🟨🟡💛
🟩🟢💚
🩵
🟦🔵💙
🟪🟣💜
🟫🟤🤎