About rendering lines

In the rendering process using OBD U6, in order to have a better effect, I set the visible edge option in the display mode, but after rendering, I found that the color of the visible edge is quite different from the color I set, because my model was built before, so that when I draw the effect picture in the later stage, the visible edge appears very inconsistent, so I need to modify the color of the visible edge to match the rendered face Colors with the same or similar colors, but do not know how to modify them, how to modify them quickly or in batches?Please give me a good way,thankyou teacher!

 Red visible edge line of steel plate and steel column in the legend

  • Also, when I lay out the guardrail, I use the guardrail tool in OBD U6 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?