Need some much needed help!

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My code so far. I'm trying to make it look like the plot above. I very much appreciate the assistance. Let me know of any mistakes!

%% Problem 1) Blackbody Radiation
% constants
%
   c = 2.99e8;	        % speed of light [m/s]
   h = 6.63e-34;	% Planck's constant [J s]
   k = 1.38e-23;	% Boltzmann's constant [J/K]
   A = 2.898e-3;	% Wein's Law constant [K m]
   T = 300;                % Earth's Temperature [K] 
   T1= 1000;             % Temperature [K] at 1000K
   T2= 6000;             % Sun's temperature [K]
   lam = logspace(-8,5,100);	% wavelength [m]
%
% Plank's Law
%  
% below are three Planck's function for T,T1,T2.
L=((2*h*c*c)./(lam.^(5))).*(exp(h*c./(lam.*k*T)-1)).^(-1);   % Blackbody curve for the Earth
Y=((2*h*c*c)./(lam.^(5))).*(exp(h*c./(lam.*k*T1)-1)).^(-1);  % Blackbody curve for T1
W=((2*h*c*c)./(lam.^(5))).*(exp(h*c./(lam.*k*T2)-1)).^(-1);  % Blackbody curve for the Sun

figure
semilogy(L,'red')    
hold on
loglog(Y,'blue')
hold on
loglog(W,'yellow')

xlabel("x")      % I don't know how to change the increments of the x-axis to reflect the above plot.  
ylabel("Spectral Radiance")
title("Blackbody Curves Plot")

Answer 1

[Image Analyst]

Try this:

%% Problem 1) Blackbody Radiation
% constants
%
   c = 2.99e8;	        % speed of light [m/s]
   h = 6.63e-34;	% Planck's constant [J s]
   k = 1.38e-23;	% Boltzmann's constant [J/K]
   A = 2.898e-3;	% Wein's Law constant [K m]
   T = 300;                % Earth's Temperature [K] 
   T1= 1000;             % Temperature [K] at 1000K
   T2= 6000;             % Sun's temperature [K]
   lam = logspace(-7, -1,100);	% wavelength [m]
%
% Plank's Law
%  
% below are three Planck's function for T,T1,T2.
L=((2*h*c*c)./(lam.^(5))).*(exp(h*c./(lam.*k*T)-1)).^(-1);   % Blackbody curve for the Earth
Y=((2*h*c*c)./(lam.^(5))).*(exp(h*c./(lam.*k*T1)-1)).^(-1);  % Blackbody curve for T1
W=((2*h*c*c)./(lam.^(5))).*(exp(h*c./(lam.*k*T2)-1)).^(-1);  % Blackbody curve for the Sun

figure
semilogy(L,'red', 'LineWidth', 2)    
hold on
loglog(Y,'blue', 'LineWidth', 2)
hold on
loglog(W,'yellow', 'LineWidth', 3)

xlabel("Log10(wavelength/m)", 'FontSize', 20)      % I don't know how to change the increments of the x-axis to reflect the above plot.  
ylabel("Spectral Radiance", 'FontSize', 20)
title("Blackbody Curves Plot", 'FontSize', 20)
grid on;
ylim([1e-10, 1e20]);

You can use text() and annotation() if you want to add the color temperature labels/text and the arrows pointing to the curves.