Im sorry for this question I'm new and it may be a stupid question, but I can't find nothing specific.
I have these differential equations and NDSolve give me InterpolatingFunctions rules for {Ca[t], Cb[t], Cc[t]}:
Solu = NDSolve[{Ca'[t] == -Ca[t], Cb'[t] == 2*Ca[t] - Cb[t], Cc'[t] == Cb[t],
Ca[0] == 1, Cb[0] == 0, Cc[0] == 0}, {Ca[t], Cb[t], Cc[t]}, {t, 0, 0.3}]
Then I Plot with this
Plot[{Ca[t], Cb[t], Cc[t]} /. Solu, {t, 0, 0.3}, PlotLegends -> {Ca[t], Cb[t], Cc[t]}]
But Plot take all the several functions, that are in a flatten list, as the same function; it shows me the legend just for Ca[t]. You see that because they have the same color.