How to put a grayscale color bar when I make a print file in illustrator

Hello guys.

I need you guys' help again.

I've made a pdf file for printing which's made up with grayscale colors

And now, I wanna set some options for printing.

By the way, when I put a setting which name's color bar

It makes of full colors not only grayscale colors

like this....(the color bar which's made of full colors are located on the sides of image)

I don't know why it happens cause of I've made a file as the Grayscale colors...

Is there any way to put the color bar that's organized with only grayscale colors in Adobe Illustrator?

If you guys know it, plz teach me!

Thx!