What Color Am I?

Come meet me after winter, I'll be smiling at the sun.
Dig me up from the soil, I go well with squash.
I'll wait on the vine so we can have cheese in a few weeks.
Grind me down, smoke me out, boil me up -
I'll make you feel relaxed, sleepy, and beautiful.

Where else have you seen me?
I have clothed your Kings, a symbol as iconic as their crowns.
I have colored your sunsets long after the sun has set.
I capped your mountain ranges, where I can see the golden waves.
I even glow as a star, surrounded by amber halos.

As a heart, I honor the dead. As a city, I am forbidden.
I am somewhere between passion and sadness.
I color the whimsical -
the romantic, conceptual unknown that inhabit dreams.
I am that feeling you have no words for -
the sudden awareness of something as old as time prodding at your senses.

What am I?