The third in our series of eight dye workshops focussing on primary colours. This week: RED. We'll mainly be using the ancient dye plant, madder, grown in our garden. Madder has been used for millennia and is familiar in the traditional Persian or Turkish carpets. We'll be creating a range of reds using 'modifiers' such as iron to go towards our Hackney Colour Wheel, our project to create a spect…