I am having a bit of hard time understanding the use of Evaluate when plotting the output of NDSolve. From the documentation, I enter:
sol = NDSolve[{y'[x]^2 - y[x]^2 == 0, y[0]^2 == 4}, y[x], {x, 1}]
Then I can plot without the use of Evaluate:
Plot[y[x] /. sol, {x, 0, 2}]
Which give this image:

Yet, when I add Evaluate (which seems to be the preference in the tutorials (currently reading tutorial/NumericalSolutionOfDifferentialEquations), but not explained in that particular tutorial, I get the following result:
Plot[Evaluate[y[x] /. sol, {x, 0, 2}]

How come this one is colored differently?