Add DiffTextWidget colors to some palettes (#8661)

* Add difftextwidget colors to Solarized palettes

* Add diff colors from https://wikilabs.github.io/editions/palette-manager/

* Add diff colors to Solar Flare palette & use yellow color for diff-invisible.

* Update solarized and solar flare palette.

core/palettes/GruvBoxDark.tid

@@ -21,9 +21,9 @@ diff-delete-foreground: <<colour foreground>>
 diff-equal-background: 
 diff-equal-foreground: <<colour foreground>>
 diff-insert-background: #b8bb26
-diff-insert-foreground: <<colour foreground>>
-diff-invisible-background: 
-diff-invisible-foreground: <<colour muted-foreground>>
+diff-insert-foreground: <<colour background>>
+diff-invisible-background: #ffff97
+diff-invisible-foreground: #444347
 dirty-indicator: #fb4934
 download-background: #b8bb26
 download-foreground: <<colour background>>

core/palettes/Nord.tid

@@ -21,8 +21,8 @@ diff-delete-foreground: <<colour foreground>>
 diff-equal-background: 
 diff-equal-foreground: <<colour foreground>>
 diff-insert-background: #A3BE8C
-diff-insert-foreground: <<colour foreground>>
-diff-invisible-background: 
+diff-insert-foreground: <<colour background>>
+diff-invisible-background: #f9f3b5
 diff-invisible-foreground: <<colour muted-foreground>>
 dirty-indicator: #BF616A
 download-background: #A3BE8C

core/palettes/SolarFlare.tid

@@ -125,6 +125,14 @@ foreground: #657b83
         tiddler-link-foreground: <<colour primary>>
 
 alert-border: #b99e2f
+diff-delete-background: <<colour red>>
+diff-delete-foreground: <<colour background>>
+diff-equal-background: inherit
+diff-equal-foreground: inherit
+diff-insert-background: <<colour green>>
+diff-insert-foreground: <<colour background>>
+diff-invisible-background: <<colour yellow>>
+diff-invisible-foreground: <<colour background>>
 dirty-indicator: #ff0000
 dropzone-background: rgba(0,200,0,0.7)
 external-link-background-hover: inherit

core/palettes/SolarizedDark.tid

@@ -18,6 +18,14 @@ button-foreground: #93a1a1
 code-background: #073642
 code-border: #586e75
 code-foreground: #93a1a1
+diff-delete-background: #dc322f
+diff-delete-foreground: #eee8d5
+diff-equal-background: inherit
+diff-equal-foreground: inherit
+diff-insert-background: #859900
+diff-insert-foreground: #073642
+diff-invisible-background: #b58900
+diff-invisible-foreground: #eee8d5
 dirty-indicator: #dc322f
 download-background: #859900
 download-foreground: #073642

core/palettes/SolarizedLight.tid

@@ -18,6 +18,14 @@ button-foreground: #586e75
 code-background: #eee8d5
 code-border: #93a1a1
 code-foreground: #586e75
+diff-delete-background: #dc322f
+diff-delete-foreground: #eee8d5
+diff-equal-background: inherit
+diff-equal-foreground: inherit
+diff-insert-background: #859900
+diff-insert-foreground: #eee8d5
+diff-invisible-background: #b58900
+diff-invisible-foreground: #eee8d5
 dirty-indicator: #dc322f
 download-background: #859900
 download-foreground: #eee8d5

core/palettes/Twilight.tid

@@ -19,13 +19,13 @@ code-background: rgba(0,0,0,0.03)
 code-border: rgba(0,0,0,0.08)
 code-foreground: rgb(255, 94, 94)
 diff-delete-background: #ffc9c9
-diff-delete-foreground: <<colour foreground>>
+diff-delete-foreground: <<colour background>>
 diff-equal-background: 
 diff-equal-foreground: <<colour foreground>>
 diff-insert-background: #aaefad
-diff-insert-foreground: <<colour foreground>>
-diff-invisible-background: 
-diff-invisible-foreground: <<colour muted-foreground>>
+diff-insert-foreground: <<colour background>>
+diff-invisible-background: #fdfcbd
+diff-invisible-foreground: <<colour background>>
 dirty-indicator: rgb(255, 94, 94)
 download-background: #19a974
 download-foreground: rgb(38, 38, 38)