how to change size and color of regions in MSERFeatures?

This uses the cameraman example here

https://www.mathworks.com/help/vision/ref/mserregions.plot.html

Two questions. How to I save the colored figure generated below at original size of image? When I save as a tiff it gets shrunk to about 25%.

How do I change the colors of the regions? For instance, instead of red, say I want [255 129 45]

I = imread('cameraman.tif');
regions = detectMSERFeatures(I);
imshow(I); hold on;
plot(regions);
figure; imshow(I); hold on;
plot(regions,'showPixelList',true,'showEllipses',false);
hold off;
saveas(gcf,'MSERTest1.tif','tiffn')

Thanks!