Color prints too dark

Here are some steps you can take to improve the print quality:

Calibrate Your Monitor:
The most common reason for prints appearing darker than the display is a mismatch between the monitor and the print. Your display should be adjusted to match the print, not the other way around.
Ensure that your monitor is properly calibrated. Use professional image editing applications like Photoshop or Lightroom to soft-proof your images. Soft proofing allows the display to simulate how the print will look.
Adjust your monitor's brightness, gamma, and color temperature to match the desired print output.

Check Your Editing Software Settings:
In Photoshop or other photo-editing apps, review your soft proofing settings. Make sure you're using the correct working space profile (such as Adobe RGB) and that it accurately represents how the image will appear when printed.
Soft proofing helps you visualize how the print will look based on the printer's ICC profile.

Printer Settings and ICC Profiles:
Understand that your printer operates independently of the display. It prints directly from the image stored on your computer's hard drive, not from the display.
The printer has no knowledge of what the display is showing. It uses its own ICC profiles to interpret colors.
Make sure you're using the correct ICC profile for your printer and paper type.

Color Management:
Color management ensures consistency between devices (display, printer, etc.). Properly managed color workflows help achieve accurate prints.
Consult your printer's user manual or online resources for specific color management instructions.

Print Test images:
Print test images with varying colors and gradients. Observe if there's a consistent issue (such as overall darkness or color shifts).
Adjust printer settings, such as brightness, contrast, and color balance, to achieve better results.

Paper and Ink Quality:
Use high-quality photo paper designed for inkjet or laser printers.
Ensure your ink cartridges are not expired or low on ink.
Remember that your display and printer use different technologies (transmitted light vs. reflected light) and have distinct color gamuts. Calibrating your monitor and understanding color management will help bridge the gap between what you see on the screen and what you get in your prints.

For detailed instructions specific to your OKI C9300 printer, refer to the user manual. What follows is how to install ICC profiles. The profile may be making your print darker.

For Windows Users:
Download the ICC Profile:
Visit the website of your paper manufacturer or other trusted sources.
Locate and download the relevant ICC profile for your printer, ink, and paper combination.
Save the profile to a convenient location (e.g., My Documents or Desktop).
Install the ICC Profile:
Right-click on the saved ICC profile file (it should appear as an RGB triangle).
Choose "Install Profile" from the context menu.
Alternatively, if you can't add the profile directly, copy it to this folder: C:/Windows/system32/spool/drivers/color.
Adjust Color Management Settings:
Open the Control Panel.
Navigate to Color Management.
Tick the "Use my settings for this device" option.
Click "Add..." and select the installed ICC profile.
In the Advanced tab, click "Change system defaults", then choose "Use Windows display calibration".
Close all windows. That's it. You are ready to rock.

It could be a paper issue. Make sure the paper you are printing on is the type paper you told the printer you installed in the paper type setting (Plain Paper, Bright White Injket Paper, etc.)

run a calibrate no about 3 times in a row, that often helps

there is a option u can do it dark and light,,,
press dark or light botton, than its gives u dark print ,,
if there is ok than change your cartridge,

Table 7-33. Causes for distortion or blurring
Cause Solution
Transfer unit is defective. Replace the transfer unit. Calibrate the printer
after replacing the transfer unit. See Calibrate
Now, later in this chapter.
Defective secondary transfer roller If it does not rotate smoothly or it is deformed,
replace the secondary transfer roller.
DC controller PCB is defective. Replace the DC controller PCB. Calibrate the
printer after replacing the DC controller. See
Calibrate Now, later in this chapter.

Calibrate Now
Use the following procedure to calibrate the printer whenever you replace the DC controller,
the formatter, the color misregistration sensor (PS12), the transfer unit, or the laser/scanner.
1. Press to enter the MENUS.
2. Press to highlight configure device.
3. Press to select configure device.
4. Press to highlight PRINT quality.
5. Press to select PRINT quality.
6. Press to highlight CALIBRATE NOW.
7. Press to select CALIBRATE NOW.
8. Wait for the printer to calibrate.
hope this helps
pdouglasss

i dont understad you problem all rigth, but maybe you need a calibration, see when was the last time 

The only time I saw a color laser Printing darker than normal the issue was tranfer belt. The condition you describe matches the problem I was involved in and the tranfer kit fixed the problem.
Hope this helps

Here's the tip I used years ago on CRT's suffering this same fate.

Take one of your printed photo's and hold it next to the screen (with the same photo on it running in whatever software you want to print from)
Now using the monitors controls, make the monitor look like your photo that you have printed.
Nice and dark now like the photo, good =)
Now adjust the software to what you want it to look like when printed.
Looking good so far..ok
Save those settings in the program. then re adjust the monitor back to how you want it to look normally (as it was before basically)

Not the ideal soloution, but it works and it's free.

If you are sure the diagnostics show the colours correctly, one thing I would look at is to see if it had a colour profile set up for it.Don't know whether this printer normally has, if it has not I would suggest reinstalling the driver. To check - Start/Printers & Faxes/ Rt click on printer then properties, look under Colour management tab. Pete