The 'FaceColor' name-value pair is not necessary in patch calls. Just use the designated colour or RGB triplet as the third argument (that patch considered to be missing here) —
myGreen = [0.0863 0.7294 0.7294];
myOrange = [0.9216 0.8157 0.1294];
x = 1:10;
yMean = rand(size(x));
ySEM = rand(size(x));
figure
patch([x fliplr(x)], [yMean-ySEM fliplr(yMean+ySEM)],myGreen,'FaceAlpha',0.2,'EdgeColor','none')
EDIT — (29 Oct 2022 at 18:24)
Corrected typographical error.
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