Try something like this —
Fs = 250;
L = 100;
f = 1.26;
t = linspace(0, L-1, L)/Fs;
s = sin([0 (1:2:20)].'*2*pi*t*f)./[1 (1:2:20)].';
ssm = sum(s);
figure
plot(t, s, t, ssm)
figure
hr = ribbon(t,[ssm; s].', 0.1);
colormap(turbo)
I leave the details (and any other improvements) to you.
.
