Looks like you don't use the Magenta ink that much, on this machine because it is so hot all the time after a while the magenta can get a strange brown colour and the cyan can get like a aqua marine colour. All you can do is purge the magenta by printing magenta sample pages or just wait until it goes away.
Also you could try the following Tek Colour correction (but It probably won't work). See below
Applies the best color correction to each graphic element: text, artwork, and photographs
Approximates the colors on a computer display.sRGB Vivid:
Produces brighter, more saturated colors than sRGB Display.
Matches specifications for Web Offset Publications.Euroscale:
Matches Fogra glossy paper specification.Commercial:
Approximates U.S. commercial press target.SNAP Press:
Matches specifications for Newsprint Advertising Production.
Applies no color correction. Use with other color management tools, such as International Color Consortium (ICC) profiles, ColorSync, or the PANTONE Color Chart for the printer.
Black & White
Converts all colors to shades of gray
From the workstation, select the color correction in a supported driver.
Microsoft Windows 98 SE / ME / 2000 / XP/ Server 2003 / NT 4.x Operating Systems (OS):NOTE:
Some of the color corrections are grouped under Office Color or Press Match.
- Within an application, click [File] from the toolbar, and then select [Print] from the menu. The Print window will be displayed.
- Click on the [Properties] button located on the top, right of the window. The Properties window will be displayed.
- Click on the [TekColor] tab.
- Select the required color correction.