export in pdf with non-homogeneous color lines

[Nunziapicardi]

Good morning to all and thank you immediately for the help you will give me.
a fast quick question:
because when I pdf a autocad file the lines have no uniform color?
I can't understand

 

[gil]

What does "homogeneous color" mean?
post an image, you understand better.

 

[Nunziapicardi]

What does "homogeneous color" mean?
post an image, you understand better.

I have only put some details magnified, in block n.1, look at the character, in n.2 in addition to the "non homogeneous" character is also seen in the line under the written mobile shears