While glow effects can easily be done with computer software on art projects, painting glow effects with acrylic paints on canvas takes some practice. The primary skill beginners need to learn is blending, which is the key to creating the glow effect. Use a painting of a candle that you have already started to begin refining your techniques at painting glow effects with just a few supplies.
Paint the candle flame, using raw umber acrylic paint and a paintbrush. Make the flame any size you like, with the bottom of the flame wide around the wick of the candle and the top of the flame tapered to a point.
Add white acrylic paint from the top of the wick portion of the flame to the tip of the flame. Use a light touch with only the very tip of your brush and blend the white paint down into the raw umber colour around the wick. Don't cover the wick. Leave a slight raw umber outline around the flame to highlight it.
Dab the tip of a dry brush in pale yellow acrylic paint. Load the tip of the brush with only a tiny amount of paint, then lightly brush the yellow paint over the white on your flame. The yellow should streak through the white, allowing some of the white to peek through. Wipe the brush with a rag between each stroke, then dab the brush in the paint again and paint with the yellow until you have streaked it through all of the white paint.
Dab the tip of a dry brush in a pale blue acrylic paint, loading the brush slightly. Then lightly streak the blue paint around the edges of the bottom of the flame, blending this hint of blue halfway up the flame at the edges. Wipe the brush with a rag after applying the blue and then, with no paint on the brush, stroke the blue colour into the bottom of the flame, blending it carefully into the other colours at the base. Leave only a small hint of blue around the bottom of the flame edge.
Load the very tip of a dry brush with pale yellow, then carefully follow the shape of the flame, about a quarter-inch to the sides of the actual flame, and paint small streaks on either side of the flame from just below the top of the flame to where the base of the flame widens. Wipe your brush with a rag and go over your glow streaks outside the flame to blend the yellow over the background, leaving the background visible through the yellow streaks. Continue going over the yellow streaks with the brush until the yellow is transparent on the painting but still evident.