Some color schemes go beyond the first 16 colors

[CtrlAltCuteness]

Problem description
Several color schemes specify colors beyond the 16 color palette. I've noticed this has been the case for many months but never reported it.

Steps to reproduce

1. Select an afflicted color scheme.
2. Display colors 16 through 21 of the 256 color palette.

Expected behavior
Colors 16 through 255 should be the same no matter which color scheme is in use.

Additional information
After extracting Termux: Styling's APK, running this grep command inside of assets/colors will show the list of files affected:

grep -Pl '^color(1[6-9]|[2-9][0-9]+)=' ./*.properties

This will show some of the colors that should be consistent no matter which color scheme is selected:

printf '\033[38;5;255m'
for i in `seq 16 21` ; do
    printf "\033[48;5;${i}m.${i}."
done
printf '\033[m\n'

• Termux application version: 0.118.0; Styling: 0.30 (F-Droid)
• Android OS version: Android 12 (One UI: 4.1; not latest)
• Device model: Samsung Galaxy S21 5G (SM-G991U)

[CtrlAltCuteness]

mii-colors.py.txt
Example Python script to assist in showing the 16 color, 256 color, and (part of) the 24-bit color sets. (Edit: Landscape orientation highly recommended if on-device)

[CtrlAltCuteness]

Using the Python script I provided, this is the default and Spacemacs (as of this time) color schemes. (EDIT) You probably can tell the difference in the first color cube.

[sylirre]

Agree for all schemes which actually cause color cube to be inconsistent like in a case with spacemacs. Some themes specify additional colors from #16 to #21. Some specify only #16. Both cases are incorrect and rather seem to be a theme porting mistake.

The full 256-color themes should be left as is. Currently they are: nancy, black-on-white, white-on-black.