Issue is shown in the image below (dark Directional Arrow):
1. From the Print Dialog, select Resymbolization > Attach Pen Table.
2. Select FDOT.tbl from the list.
3. Click the Open button.
4. From the Print Dialog, select Resymbolization > Edit Pen Table.
5. From the Modify Pen Table, highlight KeyMaps
6. Navigate to Edit > Insert New Section Below.
7. Type in DirArrows in the Name field on the Insert Section dialog.
8. Click Ok.
9. Highlight the new DirArrows section.
10. Select Cell, Complex Shape Shared Cell and Shape from the Type List on the Element Selection Criteria Tab.
11. Click the Level button on the Element Selection Criteria Tab.
12. Select the DirArrowsPavt level.
13. Select Primary from the Class list.
14. Select the Element Output Tab.
15. Toggle on Color and Fill Color, By Index and select the color 32 for both.
16. Click the Map Pen Colors button.
17. Click the Create button on the bottom of the Pen Table - Map Design Colors to Output Pen Symbology. (If the list is already populated click Edit.)
18. Select Design color 32.
19. Click the Edit button on the bottom of the Pen Table - Map Design Colors to Output Pen Symbology.
20. Click the Color button next the Print color.
21. I select a light gray color of 217,217,217. (You will need to determine the grayscale you prefer.)
22. Click the Ok button.
23. Click the Ok button on the bottom of the Pen Table - Map Design Colors to Output Pen Symbology.
24. Navigate to File > Save (or Save As) to save the changes to the Pen Table.
25. Update the preview to see if the arrow is now gray scaled to your preference.