If you have problems with your Revit Filled Region hatch patterns displaying grayscale when they should be black, its probably because Revit thinks that the lines are too close together for the scale of view that you are using.
What Revit wants is for you to increase the scale or spacing between the individual lines of the Filled Region pattern – then it will switch back to black, as it should be.
Using a Model pattern, I was able to observe the pattern go from light gray to black as I changed the scale (spacing) between the lines.
Interestingly, using a Drafting pattern allowed me to put the lines in the Filled Region much closer together…
Some more info at:
RevitCity.com | filled region pattern color changes when drawing scale changes
Hello, Interesting post. Is there evidence that drafting patterns (if complex and made of many lines of code) can negatively affect performance?