There are endless applications for color dyes, ranging from textile to plastics to paints! Very rarely does the general public get to witness the dyeing process. Luckily there's an annual tradition that opens up the world of color – dyeing of the Chicago River. St. Patrick's is a day celebrated in many parts of the globe, but the Windy City has a unique tradition. Dating back to 1962, Chicago dyes their river to a shamrock shade of green for this celebration. Thousands of visitors gather along the bridges and gorgeous riverwalk to watch Chicago transform its river.
This year, Chemworld is exceptionally proud of supplying the river dye to keep the tradition thriving! Of course, it's an environmentally-friendly dye. It fades out, allowing the river to regress back to its murky look. About 40 lbs. of this dye (physically appears to be a dark orange) is formulated into a secret recipe and plunged into the river. Multiple boats are used to dye and then churn the river. Watch the river turn bright green in the video below:
As defined by ETAD, The Ecological and Toxicological Association of Dyes and Organic Pigment Manufacturers, dyes are intensely colored or fluorescent organic substances only, which impart color to a substrate by selective absorption of light.