Having a trouble combining two plots using hold and plot3

I have an image in .mat file and can access the matrix that cointains the x,y coordinates for the it as can be seen in the comments in my code. Then I have to project it onto a plane in R³ and plot it and include in the plot a position vector. I have done all this but I am having two troubles with my plot

1. I want the pixles to be black not blue in

plot3(X,Y,Z,'o','color','b');%the image

2. This is my projected image when I only use the plot above (not hold on, add the postion vector plot, hold off). Its the way I want it, except the mentioned color problem.

Here is how the plot becomes when I add the position vector to it - why does it go to 2D

data = load('batman.mat');
%the batman image represented by a2-by-10095-matrix where the first row represent
%the x-coordinates, the second the y -coordinatesof all the pixels which are black in the image.
R = data.B; %Matrix with 10095 coordinates [x;y] 

%Project onto the plane with normal N = (1,2,3)
%Here I change the given 2D matrix to 3D by adding the third row of zeros
%for Z
col_size = size(R, 2); 
ones_row = zeros(1, col_size);
R = [R; ones_row];

P_null = [0; 0; 0;] %point of origin, the normal vector goes through
N = [1,2,3] %Normal vector
%Equation of the plane is then 1x + 2y 2 3z = dot(P_null,N) - which is 0
%Then transpose(x,y.t) = ((x,y, (1x + 2y)/-3))
A = [1 0 ; 0 1; -1/3 -2/3]; %get this matrix with two spanning vectors from above calculation
%Method of least squares
ATA = transpose(A) * A;
ATB = transpose(A) * R; %R is the origninal batman matrix, whith extra 0 row for z coordinates
x_hat = linsolve(ATA,ATB);
Final = A * x_hat
R


%cordinates for the image
X = Final(1,:,:);
Y = Final(2,:,:);
Z = Final(3,:,:);

%coordinates for the position vector
x = 10*linspace(0, 1, 100); 
y = 10*linspace(0, 2, 100); 
z = 10*linspace(0, 3, 100);

hold on
plot3(x, y, z, 'k-') %position vector
plot3(X,Y,Z,'o','color','b'); %the image
grid;
hold off

This is an example of what I am seeking after (just with a grid visible):

Answer 1

[Srivardhan Gadila]

In order to get black pixels change the color argument from 'b' to 'k' (refer to LineSpec)

plot3(X,Y,Z,'o','color','k')

In order to get both of them in same plot change the lines:

hold on
plot3(x, y, z, 'k-') %position vector
plot3(X,Y,Z,'o','color','b'); %the image
grid;
hold off

to

plot3(x, y, z, 'k-') %position vector
hold on
plot3(X,Y,Z,'o','color','k'); %the image
grid;
hold off

The following is an example code:

t = 0:pi/500:pi;
xt1 = sin(t).*cos(10*t);
yt1 = sin(t).*sin(10*t);
zt1 = cos(t)*0;
x = t-pi/2; y = t-pi/2; z = t-pi/2;

plot3(xt1,yt1,zt1,'o','color','k')
hold on
plot3(x, y, z, 'k-')
grid

Refer to the documentation of plot3, hold.