I=imread('peppers.png');
Ired=I(:,:,1);
Igreen=I(:,:,2);
Iblue=I(:,:,3);
subplot(3,3,2), imshow(I), title('Original image')
subplot(334), imshow(Ired), title('R plane BW')
subplot(335), imshow(Igreen), title('G plane BW')
subplot(336), imshow(Iblue), title('B plane BW')

Iredcolor=I;
Iredcolor(:,:,2:3)=0;
Igreencolor=I;
Igreencolor(:,:,1)=0;
Igreencolor(:,:,3)=0;
Ibluecolor=I;
Ibluecolor(:,:,1:2)=0;
subplot(337), imshow(Iredcolor), title('R plane color')
subplot(338), imshow(Igreencolor), title('G plane color')
subplot(339), imshow(Ibluecolor), title('B plane color')