I have written before on how the use of colour and highlighting can add clarity to mathematical explanations. I use colour a great deal in my everyday teaching and also when writing solutions for students to use online. With written solutions I often use a colour to indicate a part of a question and then use that same colour for a partial answer as you can see in the examples presented below. Interestingly some students prefer a series of still images (no sound) to a video as they can control the pace more easily. I present just a few examples here. Note the Algebra – factorisation example, this has proved very popular with students.