set white in bluewhitered to z=1 (instead of zero)

I'm trying to highlight z=1 in a contour plot. I have used the bluewhitered colormap in the past to help discriminate positive from negative data and I thought I could use a similar colormap where the white (or other change point color) is set to z=1. I can't figure out how to adjust hte bluewhitered colormap to do this. Does anyone have ideas for an existing colormap that might be better or one I could modify?

I have attached the plot I am working on. I am currently plotting the third subplot with the bluewhitered colorbar. I want to be able to easily see where z=1.

This is my code for the third subplot right now:

ax(3) = subplot(3,1,3)

contourf(MX,mabs,fixOMEGA,'LineStyle','none')

shading('flat');

ylabel('mab','fontsize',16);

caxis([0.5 3]);

colormap(ax(3),bluewhitered)

set(gca,'fontsize',16);

c=colorbar();

title(c,'\Omega_A_r','fontsize',16);

x = datenum('July-9-2018'):7:datenum('Oct-3-2018');

set(gca, 'XTick', x);

datetick('x','mm/dd','keepticks')