How can I shade confidence intervals and assign colors to frequency spectra plot (pwelch)

I am trying to plot power spectra for timeseries data with 95% confidence intervals. Right now I have plotted 2-3 depths of data in each spectra plot and I can plot the upper and lower confidence bounds as dashed lines. I am unsure how to the control the color of my spectra lines as well as the confidence intervals. And ideally I would like to shade the confidence interval instead of using lines. I have just made a mess so far (see attachment) . Any tips would be much appreciated. This is my first time working with this kind of plot/data. Thank you so much!

Here is my code for the plot attached:

note: I would like to ideally keep plotting the spectra in loops in case I want to add other depths (up to 9 different instruments)

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%% Combo PK spectra at NFFT = 8192

close all

f7=figure(7);

sgtitle('PK Frequency Spectra, July 23 - October 4 (NFFT=8192)')

P = .95; %confidence interval

clear nfft; nfft = 8192;

%pH

subplot(2,2,1)

clear jdo; jdo=[2,8];

for j=jdo

clear PxxU F PxxC; [PxxU,F,PxxC] = pwelch(detrend(fixgaps(PK.PH(j,spgood))),[],[],nfft,288);

h=loglog(F,PxxU,F,PxxC,'--');

hold on

end

grid on

set(gca,'fontsize',20)

xlabel('f (cpd)','fontsize',20)

ylabel('S_{pHpH} (days)','fontsize',20)

title('pH');

set(gca,'fontsize',16)

xlim([.1 10])

%legend('6.1 mab','1 mab','location','southwest')

%Oxygen

subplot(2,2,2)

clear jdo; jdo=[3 8];

for j=jdo

clear PxxU F PxxC; [PxxU,F,PxxC] = pwelch(detrend(fixgaps(PK.DO(j,spgood))),[],[],nfft,288);

h=loglog(F,PxxU,F,PxxC,'--');

hold on

end

grid on

set(gca,'fontsize',20)

xlabel('f (cpd)','fontsize',20)

ylabel('S_{DODO} (days)','fontsize',20)

title('Dissolved Oxygen');

set(gca,'fontsize',16)

xlim([.1 10])

%legend('PK 5.2 mab','PK 1 mab','location','southwest')

%Temperature

subplot(2,2,3)

clear jdo; jdo=[2 8 1];

for j=jdo

clear PxxU F PxxC; [PxxU,F,PxxC] = pwelch(detrend(fixgaps(PK.TEMP(j,spgood))),[],[],nfft,288);

h=loglog(F,PxxU,F,PxxC,'--');

hold on

end

grid on

set(gca,'fontsize',20)

xlabel('f (cpd)','fontsize',20)

ylabel('S_{TT} (days)','fontsize',20)

title(['Temperature']);

set(gca,'fontsize',16)

xlim([.1 10])

%legend('Surface','6.1 mab','1 mab','location','southwest')

%Salinity

subplot(2,2,4)

clear jdo; jdo=[2 8];

for j=jdo

clear PxxU F PxxC; [PxxU,F,PxxC] = pwelch(detrend(fixgaps(PK.SAL(j,spgood))),[],[],nfft,288);

h=loglog(F,PxxU,F,PxxC,'--');

hold on

end

grid on

set(gca,'fontsize',20)

xlabel('f (cpd)','fontsize',20)

ylabel('S_{SS} (days)','fontsize',20)

title('Salinity');

set(gca,'fontsize',16)

xlim([.1 10])

%legend('6.1 mab','1 mab','location','southwest')

Answer 1

[Jeremy]

The plot commands accept a 3 element vector in place of the built-in colors, each element being a number between 0 and 1 representing the components of red, green and blue, respectively. So, for example

plot(x,y,'Color',[1 0 0])

plots x vs. y with a red line. You can make an N-by-3 matrix of line colors to use in your loops if you want to avoid re-using colors.