Color of curves and their control elements, question 2 When I draw Bezier curves, they get initially displayed as thin black lines or curves, which can't be seen well against a dark background.

Then, later, they are displayed as thin yellow or orange lines or curves.

Where can these two colors be changed? Where can their thickness be changed?

Also, can I change the size. length, or color of vertices and control points and lines?

I'm not sure if I need this for object mode, edit mode, 2d, or 3d, sorry. I just want to change these in general, at least for now. In case it isn't obvious, I'm a beginner.

(There is a question with duplicate title that seems to discuss something not quite the same. I don't understand the answers to that question, but I cannot create comments there.)

Yes, I have tried finding this in the Manual but haven't read all of it. I have also searched the Web before posting this question. I'm posting this out of the hope that there is an expert out there who might want to help a beginner.
I don't know about the bezier curve thickness, but for the rest of the changes take a look below.

Go to user preferences (shortcut: Ctrl + Alt + U).Go to themes on the top and 3d view on the side.


Among these options,(10th row from top), 'vertex select' and 'vertex' will change the vertex colors for selected and non-selected vertices respectively.(both for bezier curves and mesh objects)



And in the 24th row, 'align handle selected' will change the handle colors of bezier curves in edit mode. Other settings for bezier curves, start with 'NURBS'



Scroll down until you see something like this.



'Vertex size' is for the size of bezier vertices and the usual mesh object vertices.