Description:
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When using php_printer on a color printer (in this case: Brother 9045CDN) printing black text only works great. But when changing the color with printer_set_option (e.g. to red), a change back to the color black ("000000") results in the printer using all 3 color toners (C, M and Y) to create the color black intead of switching back to 'black toner only'. 

On a single-page print this can be resolved by putting the change in text color after printing all black text, but on multipage prints there is no workaround possible.

Reproduce code:
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// skipped: open printer handle etc.
printer_set_option($handle, PRINTER_TEXT_COLOR, "FF0000");
printer_draw_text($handle, "TEST", 0, 0);	printer_set_option($handle, PRINTER_TEXT_COLOR, "000000");
printer_draw_text($handle, "TEST", 0, 100);	
// skipped: close printer handle etc.


Expected result:
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The printer should use the black toner/cartridge only after selecting black as printer text color again. 

Actual result:
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The printer mixes C, M and Y toner to create black, instead of the black toner (and the black toner only), resulting in more coslty and less sharp printouts. Reproducing a similar print in Openoffice or Word results in the printer correctly using black toner only.