India, July 26 -- I ate plenty of mithai growing up. But the memory of one dish has stayed with me: a bowl of pink payasam from a temple in Kerala. Its magic lay in two things: its luxurious texture, created by the long reduction of milk and the simmering of starches; and its unmistakable pink hue. Part of that colour came from the broken red rice used. But red rice is not the only path to pink payasam. Pressure-cook milk and sugar together and the gentle caramelisation can add a brown hue that, when mixed with milk, looks pale pink. The ratio is vital here. The more sugar, the darker the hue. I use a quarter cup of sugar for every cup of milk. Colour can be one of the most intriguing tricks to play with in the kitchen. Humans instinctively associate certain tints with flavours. Good cooks understand this. Food marketers do too. So, in a number of foods, what begins as a genuine indicator of quality is often strategically recreated. Take the dosa. A beautifully browned one instantly signals flavour (from the Maillard effect). One sees the dosa and immediately pictures fluffy batter on a hot griddle, the drizzle of ghee, and the edges crisping up. Shortcuts include adding naturally reddish-brown foods such as fenugreek seeds or red rice to the traditional mix for the batter. A bit of sugar can also help, and that's a hack I'll admit I sometimes use at home. Perfectly browned potatoes are often not perfectly browned either. That takes time, and just the right balance of low moisture, high heat and an alkaline environment. Instead, look closely at a number of social-media posts and one can see that a dark spice paste has been used to create the illusion of that delicious rough, crisp texture. Most mass-manufactured cheddar cheese, meanwhile, has changed colour completely, as companies chased the perfect hue. It was the beta carotene in fresh grass that gave cow's milk its mild orange-yellow, a pigment that passed into milk fat, producing naturally yellow butter and cheese. Across most of the world, this was only possible in summer. The rest of the time, the cows ate grain and the pigment faded away. Meanwhile, buffaloes, goats and sheep convert beta carotene into colourless Vitamin A. So, even grass-fed, their milk could only produce white butter and cheese. To keep things consistent, manufacturers began to add natural dyes to cheddar cheese. Today, the deep orange tint from those ingredients, rather than the original pale yellow, has become part of cheddar's identity. My favourite hue hack in the kitchen? A tablespoon of canned tomato paste, to give my curries a rich colour. Fresh tomatoes tend to stay pinkish when cooked, because they hold so much water. It takes quite a long time - and plenty of tinkering with the rest of the dish - to get that water to evaporate and lead to a deeper red. A spoon of paste delivers that rich red look and deep tomato flavour instantly....