How to change axis label and box colour when using pcolor with contours

I'm producing plots in a row with insets using the 'axes' command. All the plots are pcolor surface plots with overplotted contours. I'd like the inset plots to have a white border and white numbers along the x and y axes, so that it stands out from the background, but the contours within the plot to remain black. I can't seem to isolate those properties. I've tried the following (I'm producing the plots in a row using the subplot command, I'm not sure if that has any relevance). I have to set the 'EdgeColor' to 'none' otherwise I get grid marks all through the plot and that's not what I want.

subplot(1,3,3)
shading interp
colormap(jet)
hold on
NP=pcolor(Xsurf,Ysurf,Zsurf);
contour(Xsurf,Ysurf,Zsurf,'-k','ShowText','on')
shading interp
hold off
set(NP,'EdgeColor', 'none');

LPa=axes('position',[0.8 0.5 0.11 0.33])
hold on
LP=pcolor(Xsurf2,Ysurf2,Zsurf2)
LPc=contour(Xsurf2,Ysurf2,Zsurf2,[5,10,20,40],'-k','ShowText','on')
set(gca,'box','on')
shading interp
hold off
set(LP,'EdgeColor', 'none');