The Hexidecimal Rainbow image is pure web designer geeky fun.
Each color in the rainbow is represented by its RGB hexidecimal code. The entire rainbow makes a mid-20th century style supergraphic. To highlight this, I used it at various sizes and angles on different products.
This was one of my early graphic designs intended for print on demand merchandise. I did not have professional design software yet, so I used Inkscape, a high level open-source vector art program.
I used the image on a variety of Merchandise at Zazzle.
Inkscape, to create the curved text. Inkscape is an open source vector graphics program.
If I were to re-make the image, I would use Adobe Illustrator or InDesign, or Bohemian Coding’s Sketch.