AutoCAD Plots in Color Instead of Black
The drawing should produce monochrome output, but the PDF or paper contains colored lines. Start by identifying exactly where the problem first appears, then test the most likely causes one at a time. This avoids changing a correct drawing to compensate for a PDF, driver or printer problem.
Symptoms — confirm exactly what is wrong
- The drawing should produce monochrome output, but the PDF or paper contains colored lines.
- If every object is wrong, suspect the shared Page Setup or plot-style workflow; if only a few objects are wrong, inspect their layer/color/style first.
- Pick one affected object and trace it from object/layer properties through CTB/STB to Plot Preview.
Beginner rule: Change one setting at a time. After each change, repeat the same test so you know what actually fixed the problem.
30-second triage: Look at Plot Preview. If Preview is already colored or has wrong weights, stay in AutoCAD’s CTB/STB, Plot Options, object/layer and viewport settings. Do not start by changing the PDF preset.
Likely causes — check these in order
| Likely cause | Why it creates this symptom | Quick check |
|---|---|---|
| Monochrome plot style is not being applied as expected | The drawing may use another plot-style mode/table or objects may use true color behavior outside the expected ACI mapping. | Check PSTYLEMODE, selected table and the affected object’s color. |
| Wrong CTB/STB is selected | The plot style table is changing colors, screening or lineweights differently from the standard. | Open PAGESETUP > Plot Style Table and compare the selected file. |
| Plot with Plot Styles is turned off | When this option is off, AutoCAD plots object properties without applying the selected CTB/STB overrides. | Open PAGESETUP > Modify > Plot Options and confirm Plot with Plot Styles is selected. |
| Objects or layers use True Color (RGB) | A CTB is color-dependent and maps AutoCAD Color Index (ACI) colors; True Color objects can remain colored instead of following the expected monochrome mapping. | Select one colored object and its layer, then inspect Color in Properties/Layer Properties for True Color versus an ACI color. |
| The viewport uses a 3D visual style or Shade Plot setting | Realistic, Conceptual or other shaded output can be rasterized and can bypass the expected 2D monochrome result. | Select the viewport > Properties and inspect Visual Style / Shade Plot; compare with the project’s approved 2D Wireframe or output setting. |
| Viewport layer override | A viewport can override color, lineweight, transparency or plot style for one Layout view. | Activate the viewport and inspect VP Color / VP Lineweight / VP Plot Style. |
For the underlying setup behind these checks, use monochrome.ctb Not Working and How to Apply a CTB to an AutoCAD Layout while you diagnose the symptom.
Diagnostic path — isolate the responsible setting
Work through the checks in order. Do not apply a fix until its diagnostic check differs from the known-good project standard.
Diagnostic 1 — Monochrome plot style is not being applied as expected
Where: PAGESETUP > Modify > Plot Style Table, and STYLESMANAGER when the table itself must be inspected.
Do this: Check PSTYLEMODE, selected table and the affected object’s color.
Check: If this differs from the known-good project standard, correct it and retest before continuing.
Diagnostic 2 — Wrong CTB/STB is selected
Where: PAGESETUP > Modify > Plot Style Table, and STYLESMANAGER when the table itself must be inspected.
Do this: Open PAGESETUP > Plot Style Table and compare the selected file.
Check: If this differs from the known-good project standard, correct it and retest before continuing.
Diagnostic 3 — Plot with Plot Styles is turned off
Where: PAGESETUP > Modify > Plot Options.
Do this: Open PAGESETUP > Modify > Plot Options and confirm Plot with Plot Styles is selected.
Check: If this differs from the known-good project standard, correct it and retest before continuing.
Diagnostic 4 — Objects or layers use True Color (RGB)
Where: Select an affected object > Properties, then Layer Properties Manager.
Do this: Select one colored object and its layer, then inspect Color in Properties/Layer Properties for True Color versus an ACI color.
Check: If this differs from the known-good project standard, correct it and retest before continuing.
Diagnostic 5 — The viewport uses a 3D visual style or Shade Plot setting
Where: Layout > select/activate the affected viewport > Properties, then PAGESETUP > Shaded Viewport Options.
Do this: Select the viewport > Properties and inspect Visual Style / Shade Plot; compare with the project’s approved 2D Wireframe or output setting.
Check: If this differs from the known-good project standard, correct it and retest before continuing.
Diagnostic 6 — Viewport layer override
Where: Layout > double-click inside the affected viewport > Layer Properties Manager.
Do this: Activate the viewport and inspect VP Color / VP Lineweight / VP Plot Style.
Check: If this also matches the known-good setup, use the isolation test below instead of changing unrelated settings.
Fixes — use only the fix that matches your diagnosis
Fix 1 — Fix the monochrome workflow
Use this fix when: your diagnosis confirmed that Monochrome plot style is not being applied as expected.
Do this: Confirm the drawing uses the expected CTB/STB mode, select the approved monochrome table and check the affected object’s color/plot-style assignment.
Check: Run Preview on the same test object and compare color/lineweight with the reference output.
Fix 2 — Select the approved CTB/STB
Use this fix when: your diagnosis confirmed that Wrong CTB/STB is selected.
Do this: Open PAGESETUP > Plot Style Table and choose the controlled project table. Test one calibration sheet before batch publishing.
Check: Run Preview on the same test object and compare color/lineweight with the reference output.
Fix 3 — Turn Plot with Plot Styles back on
Use this fix when: your diagnosis confirmed that Plot with Plot Styles is turned off.
Do this: Open PAGESETUP > Modify > Plot Options, select Plot with Plot Styles, save the named Page Setup and run Preview again.
Check: Run Preview on the same test object and compare color/lineweight with the reference output.
Fix 4 — Return the affected objects to the approved color standard
Use this fix when: your diagnosis confirmed that Objects or layers use True Color (RGB).
Do this: If the office CTB workflow is based on ACI colors, change the affected object/layer from True Color to the approved ByLayer/ACI value, then Preview again.
Check: Run Preview on the same test object and compare color/lineweight with the reference output.
Fix 5 — Use the approved viewport visual style and Shade Plot setting
Use this fix when: your diagnosis confirmed that The viewport uses a 3D visual style or Shade Plot setting.
Do this: Set the viewport/Page Setup to the office-approved 2D plotting configuration, then Preview before changing the CTB again.
Check: Run Preview on the same test object and compare color/lineweight with the reference output.
Fix 6 — Remove or correct the viewport override
Use this fix when: your diagnosis confirmed that Viewport layer override.
Do this: Activate the viewport, open Layer Properties Manager and reset the specific VP Color/Lineweight/Plot Style override that is causing the output difference.
Check: Run Preview on the same test object and compare color/lineweight with the reference output.
Verification — prove the fix before full production
- Preview one known test object and one known-good object side by side.
- Confirm the selected CTB/STB and Plot with Plot Styles setting.
- Create a PDF and compare color, screening and lineweight hierarchy with the reference output.
- Only then run the full sheet set or physical plot.
Still not fixed? Use an isolation test
Plot a small calibration sheet with known colors and lineweights through the same Page Setup. If the calibration is wrong too, the problem is shared; if it is correct, return to the affected objects/layers.
Prevention — reduce the chance of recurrence
- Keep one controlled master CTB/STB and deploy the same version to every workstation.
- Use a calibration drawing with representative ACI colors, screening and lineweights.
- Document whether the project uses ACI/ByLayer colors, True Color, CTB or STB.
- Retest after plot-style, viewport-override or driver changes.
Official Autodesk references
Use these references when the interface, driver or plot-style behavior on your workstation differs from the checks above.
Frequently asked questions
Why can monochrome.ctb still produce colored objects?
Check Plot with Plot Styles, True Color objects/layers, the drawing plot-style mode and shaded/3D viewport output before assuming the CTB file is bad.
What if only a few objects stay colored?
Inspect those objects and their layers for True Color, block-contained colors or viewport overrides instead of changing the whole Page Setup.
Should I switch PDF presets to fix this?
Not first. If Plot Preview is already colored, the problem is inside AutoCAD’s plotting/style workflow rather than the saved-PDF preset.
Explore more in CAD Printing & Plotting Troubleshooting.