riddle - Some grew to remember me!

Here's a quick easy one.

Some grew to remember me,
On the ground, or up a tree,
I play well with R&B,
In large amounts, a sight to see.

Throughout a valley, over hill,
A thing for which some men would kill,
I may be new, or if you're ill,
Round something yours that rhymes with chill.

What am I?

Answer

It could be

The colour green

Some grew to remember me

Primary Colours; red, green and blue

On the ground or up a tree

Grass and Leaves

I play well with R&B

RGB colours; Red, Green and Blue

In large amounts, a sight to see

Large open fields

Throughout a valley, over a hill

Hills and valleys tend to be green

A thing for which some men would kill for

Money

I may be new, or if you're ill

Green is used to describe something new. Sick people are described as going a shade of green

Round something yours that rhymes with chill

'Green around the gills'

Thanks @Silenus for filling in the blanks