Adding a color will begin a script checking cycle, followed by permanently adding the color to the card or background. If the Crayon finds a problem with the script, it will notify you and offer to fix it. You can choose to let it fix the script for you or not, but if you don't the color will not be added.
Additionally, you will be asked if you want to convert the Crayon to an ordinary button. If you answer "Yes," you'll get this dialog:
You may wish to keep your frame as a regular button so that you can associate an action with clicking on the color. The rest of the options are fairly self-explanatory. Deleting the button from this dialog will not erase the picture as the button deletes itself.
All Crayons reveal their workings in the top lines of their scripts:
-- "7805,27555,65535" <--This is the current color
-- 19,181,111,327 <--- This is the current coloring rect
(Line 1 being the colorize command, line 2 being the Crayon's color in RGB format, and line 3 being the rect of the Crayon.)
These scripts update themselves as you move or change the attributes of your Crayons. Make sure that you toggle the Crayon on and off fully before copying a command from the Crayon script for direct pasting. Otherwise, you may end up with the Crayon's previous position. Crayons take care of updating themselves when you use the option click method to add them to your cards or backgrouds.
A few rules apply to Crayons. Card Crayons will overlay background or stack Crayons (as you would want them to), and on a card, the Crayons you add first will be covered or partially covered by any that you place on them and save afterwards. In other words, the sooner they go in, the deeper they are in the layer.
A scripting guide is available for registered users. You may also want to look at the original colorizeHC stack from BungDabba Productions for further information. Some of my methods are a little tricky, so make sure you understand the message passing order before you start trapping the messages in your stacks. You'll know you failed to grasp how things work if you get a dialog that says "Too much recursion."