SVD decomposition on color image?

I am trying to preform SVD Decomposition on a color image. I have attached my code. The main goal is to preform SVD on a color image, and apply various rank approximations. The issue is when i change the rank to k=55, I get a greyscale image and not color. How could I fix this to get a color image when I change the rank?

% Read jpg file

A = imread('woodchuck.jpg');

% Convert to A to double

A = im2double(A);

% Color Channels

R = A(:, :, 1);

G = A(:, :, 2);

B = A(:, :, 3);

% Perform svd

[UR,SR,VR] = svd(R);

[UG,SG,VG] = svd(G);

[UB,SB,VB] = svd(B);

DR = UR*SR*VR';

DG = UG*SG*VG';

DB = UB*SB*VB';

%Create new matrix

% Plot rank 5 approximation, rank 10 approximation, rank 50, and true image

figure('Position',[50 50 800 800])

subplot(2,2,1)

M=zeros(480,640,3);

M(:,:,1) = DR;

M(:,:,2) = DG;

M(:,:,3) = DB;

imshow(M); title ('Original Image')

subplot(2,2,2)

k = 55;

Mk = UR(:,1:k)*SR(1:k, 1:k)* VR(:,1:k)';

Mk = UG(:,1:k)*SG(1:k, 1:k)* VG(:,1:k)';

Mk = UB(:,1:k)*SB(1:k, 1:k)* VB(:,1:k)';

imshow(Mk); title('Rank 55')

[Christine Tobler]

The lines

Mk = UR(:,1:k)*SR(1:k, 1:k)* VR(:,1:k)';

Mk = UG(:,1:k)*SG(1:k, 1:k)* VG(:,1:k)';

Mk = UB(:,1:k)*SB(1:k, 1:k)* VB(:,1:k)';

each overwrite Mk with the next channel, so you're only seeing a grayscale image with the last channel (blue). Use Mk(:, :, 1) = ..., Mk(:, :, 2) = ..., Mk(:, :, 3) = ... instead.

[Jeremy Dessert]

Thanks for the suggestion that worked!