browser.uidensity is set to 0 by default.  Changer the  value to 1 and it takes immediate effect.

Joplin Web Clipper, Zotero Connector, floccus bookmarks sync, uBlock Origin, Quick Javascript Switcher, SingleFile, uMatrix

Firefox:

floccus bookmarks sync, Joplin Web Clipper, Search by Image, uMatrix, Undo Close Tab, Zotero, uBlock Origin

[x]  Removed some Firefox/LibreWolf extensions

[+] Added Zotero and uBlock Origin, which have been long used, but neglected with regards to appearing in this list.

{
    "policies": {
    "DisableAppUpdate": true
    }
}

Thanks to sifferedd.

alias ll=’ls -alF’
alias la=’ls -A’
alias l=’ls –CF’

To eliminate the DRM warning in Firefox and Librewolf without enable DRM, add this to “userChrome.css”:

 notification[value="drmContentDisabled"]{ display:none !important; }

toolkit.legacyUserProfileCustomizations.stylesheets must be set to true in about config.

The Thunderbird developers are moving to a new user interface code base for Thunderbird 115 and Thunderbird 102 is the last version that will work with the historical userChrome.css customizations. The userbase for Mozilla products has continually shrunk over the past few years and the chances of equivalent customization abilities being discovered and written about strike me as pretty low.  Because of the change, I have mirrored Thunderbird 102.14 for Windows and Linux in 64-bit and 32-bit versions in the event that the old versions disappear from the Mozilla site. The Source is available on the Mozilla mirror as of August 11, 2023.  The releases are located here.

The userChrome.css below allows the following persistent tag colors.  It also contains text customization for the interface.  And it contains alternate row highlighting, where one row is light grey and the other white.  The alternate row highlighting conflicts with the background colors for tags.  One must choose which feature to have. The userChrome.css goes in the profile directory in a subfolder called chrome.

The code for highlighting the tag backgrounds was found on a French website located here. E.g. C:\Users\username\AppData\Roaming\Thunderbird\Profiles\1a2b3cde.default-release\chrome

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
/* set default namespace to XUL */
/* thanks to Jean-Claude, */
/* https://forums.mozfr.org/viewtopic.php?t=143173 */
/*Important tag IMPORTANT*/ 
treechildren::-moz-tree-row(T_24label1)
{
      border-bottom: 1px solid #FFFFFF !important;
      background-color:  #FF0033   !important;
}
treechildren::-moz-tree-cell-text(T_24label1)
{
      color: #FFFFFF !important;
}
treechildren::-moz-tree-row(T_24label1, selected)
{
      background-color: #b71c1c !important;
}
treechildren::-moz-tree-cell-text(T_24label1, selected)
{
  color: #00FF00  !important;
}

/*Travail tag   WORK*/
treechildren::-moz-tree-row(T_24label2)
{
  border-bottom: 1px solid #FFFFFF !important;
  background-color:  #FF9900   !important;
}
treechildren::-moz-tree-cell-text(T_24label2)
{
  color: #FFFFFF !important;
}
treechildren::-moz-tree-row(T_24label2, selected)
{
  background-color: #FF9900 !important;
}
treechildren::-moz-tree-cell-text(T_24label2, selected)
{
  color: #00FF00  !important;
}

/*Personnel tag PERSONAL*/ 
treechildren::-moz-tree-row(T_24label3)
{
  border-bottom: 1px solid #FFFFFF !important;
  background-color:  #009900   !important;
}
treechildren::-moz-tree-cell-text(T_24label3)
{
  color: #FFFFFF !important;
}
treechildren::-moz-tree-row(T_24label3, selected)
{
  background-color: #009900 !important;
}
treechildren::-moz-tree-cell-text(T_24label3, selected)
{
  color: #00FF00  !important;
}

/*A faire tag*/
treechildren::-moz-tree-row(T_24label4)
{
  border-bottom: 1px solid #FFFFFF !important;
  background-color:  #3333FF   !important;
}
treechildren::-moz-tree-cell-text(T_24label4)
{
  color: #FFFFFF !important;
}
treechildren::-moz-tree-row(T_24label4, selected)
{
  background-color: #3333FF !important;
}
treechildren::-moz-tree-cell-text(T_24label4, selected)
{
  color: #00FF00  !important;
}

/*Peut attendre tag*/
treechildren::-moz-tree-row(T_24label5)
{
  border-bottom: 1px solid #FFFFFF !important;
  background-color:  #993399  !important;
}
treechildren::-moz-tree-cell-text(T_24label5)
{
  color: #FFFFFF !important;
}
treechildren::-moz-tree-row(T_24label5, selected)
{
  background-color: #993399 !important;
}
treechildren::-moz-tree-cell-text(T_24label5, selected)
{
  color: #00FF00  !important;
}

/*test tag*/
treechildren::-moz-tree-row(Ttest)
{
  border-bottom: 1px solid #FFFFFF !important;
  background-color:  #FFCC33  !important;
}
treechildren::-moz-tree-cell-text(Ttest)
{
  color: #FFFFFF !important;
}
treechildren::-moz-tree-row(Ttest, selected)
{
  background-color: #FFCC33 !important;
}
treechildren::-moz-tree-cell-text(Ttest, selected)
{
  color: #00FF00  !important;
}

/* 9 August 2023 Additions */
/* Set Font Size In Folder Pane */

#folderTree >treechildren::-moz-tree-cell-text {
  /*font-family: Lucida Sans !important;*/
  font-size: 9pt !important; }

/* Set Font Size In Thread Pane */

#threadTree >treechildren::-moz-tree-cell-text {
  /*font-family: Lucida Sans !important;*/
  font-size: 9pt !important; }

#threadTree treechildren::-moz-tree-row    {
/*  border-bottom: 1px dotted grey !important;  */
  height: 24px !important; }

/* folder list spacing */

#folderTree treechildren::-moz-tree-row    {
  height: 24px !important; }

/* The silver background color on alternating rows */
#threadTree treechildren::-moz-tree-row(odd) {
  -moz-appearance: none !important;
  background-image: none !important;
  /* the !important property overrides previous styling rules */
  /* this line enables alternate color row highlighting, but
  tag backgrounds on this row cannot be highlighted.  Only one 
  background highlighting can be applied Disabled 9 August 2023
  to enable tag background highlights*/
  /* background-color:#F3F6FA !important; */

}

#threadTree treechildren::-moz-tree-row(selected) {
  background-color: -moz-Dialog !important;
}
#threadTree treechildren::-moz-tree-row(selected, focus) {
  background-color: Highlight !important;
}

#folderTree treechildren::-moz-tree-row(selected) {
  -moz-appearance: none !important;
  background-image: none !important;
  background-color: Highlight !important;
}
#folderTree treechildren::-moz-tree-row(selected, focus) {
  -moz-appearance: none !important;
  background-image: none !important;
  background-color: Highlight !important;
}