A paint from India
Indian yellow was a real pigment, sold in India as purree or piuri. Its main parts are salts of euxanthic acid. Mixed with water or oil, it gave a clear, deep orange yellow that glows in sunlight because it is fluorescent. Painters at the Mughal and Rajput courts used it in small, detailed pictures from the 16th to the 19th century. European artists bought it too, mostly in the 1800s. By about 1921 it could no longer be bought.
The story of the cows
For a long time nobody in Europe knew how it was made. In 1883 T. N. Mukharji wrote that he had seen it made in Monghyr, in Bihar. Cows were fed only mango leaves, and their urine was boiled down, strained and pressed into balls. The writer Victoria Finlay later doubted this, because she found no other written record of it. In 2018, scientists tested part of a sample Mukharji had sent to Kew Gardens in England. It held hippuric acid, a marker of urine, which backs up his account. The Wikipedia article on Indian yellow tells the full story.
Paint makers today sell an Indian yellow hue made from synthetic pigments such as nickel azo and hansa yellow.
The screen color
The code #E3A857 comes from an old web list called The Mother of All HTML Colo(u)r Charts. It is a soft, sandy version and lacks the glow of the real paint. Almost the same code belongs to sunray, and earth yellow is very close. For a brighter golden pigment, see gamboge.