Changing the theme color bar and compile failing

I have copied the Default theme.

I then go into the .less files for the site.
variables.plone.less

I change the color from blue to
@plone-sitenav-bg: #000000;

I save the file.

Then I compile the BARCELONETA.plone.less file.

The saved variables.plone.less file retains the #000000 color change, but the site theme does not retain it.

It reverts back to
.plone-navbar {
background-color: #007bb1;

What steps am I missing?

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