First of all, you need to choose a colour that want to use on the fireplace bricks. Make sure the paint colour that you choose does not look odd with the overall appearance of your room.
You need to be creative in order to decide the colour of your fireplace bricks and there are many paints that offer different designs as well. Make sure you make the right selection in the colour of the paint.
Take sandpaper and rub it over the surface of bricks which will remove if there are any loose pieces of mortar. Use vacuum for removing dirt or dust from the bricks.
Take a bucket filled with soapy water and dip a cloth or brush in this water. Now take this cloth or brush and rub it on the bricks in order to make it completely cleaned. Leave it for a while to dry.
If you do not want to paint certain areas of the fireplace bricks then tap off these areas. Tapping off these areas will help you to avoid rubbing or removing paints from unwanted areas after the completion of paint because you already have left them.
Now take a primer which is usually used in masonry projects. You can also use thick nap-roller in order to cover the surface of the bricks and then use the brush to cover the grout. Leave it to dry.
After that you should apply paint colour to the surface of the bricks. Make sure you have selected a top quality latex paint. Use a roller brush to start applying paint to the bricks.
Apply at least 2 to 3 coats of paint which will give your fireplace a new look which will last for a longer period of time.