my mac will only order my printer to print in black and white (Printer is an HP Photosmart 5520). when my son prints he manages colour. so i assume its in my settings but cannot find where to change from b/w to colour??

When you print you should see a print dialog similar (but not necessarily exactly) like the above. You can see a red arrow above pointing to a pop-up menu right below the orientation buttons. Click on the menu item and you’ll see other menu items including one that should mention color. On my computer it says Color Matching. When I select that menu item a couple options appear that let my choose either Color Sync or In Printer - that controls whether Apple’s color matching scheme is used or the printer’s. Click on ColorSync if it isn’t already chosen and look in the list below that for your printer brand and RGB. (see below) My first thought is that your computer has the Gray version selected.