How can I colour the two regions inside the triangle upper and down the parabola plotted together but with different intervals of the variables? The input text I wrote in Mathematica is
Show[
Plot[{1/3 - 2/3 γ}, {γ, 0, 1/2}, AxesLabel -> {γ, λ}, PlotStyle -> CMYKColor[0, 0, 0, 1]],
Plot[γ^2, {γ, 0, 1/3}, AxesLabel -> {γ, λ}, PlotStyle -> CMYKColor[0, 0, 0, 1]]]
Plot[{1/3 - 2/3 γ, ConditionalExpression[γ^2, 0 <= γ <= 1/3]}, {γ, 0, 1/2}, AxesLabel -> {γ, λ}, Filling -> {2 -> {1}}, PlotStyle -> Black]
$\endgroup$