Your printer should automatically print the same colours as are on your screen. So if (oddly?) you want to print your letter to the vicar out in bright green, you need to change the colour of your text on the screen (in Microsoft Word, OpenOffice Writer or whatever), rather than seeking to change it through the printer settings.
Are you using Microsoft Word or something else to type your documents? (I seem to remember that you were using Abiword at one time but that was ages ago, so you might be using something else now).
Start by highlight the text that you want to change the colour of. If it's just part of the document, drag your mouse over it while holding the left button down. If it's all of the text that you want to select, try pressing the Ctrl and A keys together. (Both of those work with every Windows program I've ever come across but I've never used Abiword).
Next, brng up the Font dialogue box. To do that either go to 'Format' and then click on 'Font' or simply press Ctrl and D together.
Click on the little arrow to the right of the Color command in the Effects box and then select the desired color from the list.