I figured this out quite by accident, and I will show you why, but the short answer to your question is to Find the length of the command and then display that. For example, consider the plot function.
In[50]:= Length[Plot[x, {x, 0, 1}]]
Out[50]= 2
Now we can look at these two elements and you will see all:
You can see the hue (Hue[0.67, 0.6, 0.6]
) of the classic blue line in
Plot[x, {x, 0, 1}][[1]]
You can see all sorts of other hidden details in
Plot[x, {x, 0, 1}][[2]]
For example, the default aspect ratio is 1/GoldenRatio
.
I will show you how I found this, why, and how I changed a function that I could not otherwise change. I was trying to make polyhedral nets, and the function
PolyhedronData["Disphenocingulum", "NetImage"]
gives a net, but there is no way to change this baby barf yellow color. What I did was this. I computed and looked at
PolyhedronData["Disphenocingulum", "NetImage"][[1]]
I saw that this ugly yellow was RGBColor[1, 1, 0.85]
. I replaced the regular polyhedron data function with
Graphics[
ReplacePart[
PolyhedronData["Disphenocingulum", "NetImage"][[1]],
1 -> FaceForm[RGBColor[1, 1, 1]]]]
Eureka, I made the background white and never gave it a second thought until today. I feel like I answered your question. As for me, I had no choice but to find these hidden details, as I could not figure out how to manipulate the built in function otherwise.
I think this method should show the hidden guts of pretty much every function you have in mind.