This is the second of three items on the under painting, following the first; Sheffield railway station. The same rules apply: a minimal sketch, broad washes to represent the main lighting scheme, in this case using Cad Red, Cobalt blue with Alizarin hints for the blue-violet, and Raw Sienna for my yellows, applied with a hake, in volume (you can see the bead of Cad Red at bottom right, since I worked at an easel). It's important to develop an understanding of mixture content when laying these preliminary washes. It's quite a wet process and pigment will dissipate leaving passages maybe lighter than you wanted in the finished article. Compensate for this - you only get one chance. The major light source is from above and left, so I've developed the painting with raw sienna on the sunny right and deep violets on the shaded left. Don't be shy about the figures; the mixtures must be rich to get the contrast and the feel of the day, especially in flesh tones, where students often go limp, undermining what is being said. In the third stage I've picked out some major shapes with rich colour and used a bunch of semi-abstract watercolour marks in the final stage to suggest the rest of the paraphernalia down the centre. White body colour picks out signage, highlights figures and adds trinkets to provide scale and an air of busyness.