Spatial plot land part in gray color

I am plotting a spatial plot, I want land parts should be in gray or white colour. The code I am attaching is not working

figure;

imagesc(lon, lat, corr_coeff_weak'); 
set(gca, 'YDir', 'normal'); 
colorbar;
colormap(redblue); 
caxis([-1 1]); 
xlabel('Longitude');
ylabel('Latitude');
title('Correlation for Weak SST Years');
hold on;
load coastlines;
fill(wrapTo360(coastlon), coastlat, 'w', 'EdgeColor', 'none'); % Fill land with white
plot(wrapTo360(coastlon), coastlat, 'k.', 'MarkerSize', 4); 
axis xy;

[Mathieu NOE]

hello

can you provide corr_coeff_weak data ?

[Austin M. Weber]

Have you tried plotting your data using a map axes instead? With the axesm function you can specify to plot longitudes from 0 to 360 instead of -180 to +180. For example:

load coastlines
figure;
axesm('Robinson','MapLonLimit',[0 360])
fillm(coastlat,coastlon,'FaceColor','#505050','EdgeColor','none')
framem
gridm
box off
set(gca,'YColor','none','XColor','none')