A short JavaScript code to turn 16x16 images into blocks of text that work with Cesium for the TI-84 Plus CE (and possibly Doors CS for the CSE). Open it at https://onlymx13.github.io/cesium-color-helper. This will convert the image to 16x16 first, so no need to worry about that.

Paste the output into TI-Connect CE. :DCS will be in the first line of the program. There will be two colons there once it's sent to the calculator. A " will be in the second line and then there will be some text from this tool there. This should all be part of the output so just paste it in TI-Connect CE. Then put the rest of your program on line 3 and below. Save it and send it to a real calculator or CEmu (https://github.com/CE-Programming/CEmu). A preview will also be shown, which gives a general idea of the appearance of the colors of the icon on the calculator.