about render line

I am using OBD In the process of U6 rendering the structure, in order to achieve the effect, I set the visible edge in the view. After rendering, the theme color changes, but the visible edge display does not change, which leads to the incongruity between the color of my rendering and the color of the visible edge, which affects the effect of the rendered effect map. Which God can help me to solve the problem of the visible edge, that is to say The visible edge can be modified freely or quickly in batch. The principle and process can be more detailed?

Also, when I lay out the guardrail, I use the guardrail tool in OBD U5 to lay out the guardrail directly. The layer should be one layer. But after I add the rendered material (yellow), why do some parts become the color I need, and some parts (shown as blue) do not change?

thanks teacheer!