added four new theme to the theme directory

[Gopinath-Mahendiran]

What does this PR do, and why?

This PR adds four new themes to Zulip Terminal, enhancing user customization options and improving the overall visual experience. The newly introduced themes offer greater flexibility for different user preferences.

Added new theme are
->gruvbox_dark_high_contrast
->gruvbox_dark_low_contrast
-> gruvbox_light_high_contrast
-> gruvbox_light_low_contrast

External discussion & connections

• Discussed in #zulip-terminal in topic
• [] Fully fixes #
• Partially fixes issue Use common-background code to enable variants of themes (eg. gruvbox contrast settings) #1535
• Builds upon previous unmerged work in PR #
• Is a follow-up to work in PR #
• Requires merge of PR #
• Merge will enable work on #

How did you test this?

• [ x] Manually - Behavioral changes
• [x ] Manually - Visual changes
• [ x] Adapting existing automated tests
• Adding automated tests for new behavior (or missing tests)
• [ x] Existing automated tests should already cover this (only a refactor of tested code)

Self-review checklist for each commit

• It is a minimal coherent idea
• It has a commit summary following the documented style (title & body)
• [ x] It has a commit summary describing the motivation and reasoning for the change
• It individually passes linting and tests
• It contains test additions for any new behavior
• [ x] It flows clearly from a previous branch commit, and/or prepares for the next commit

Visual changes

gruvbox_dark_high_constrast

gruvbox_dark_low_constrast

gruvbox_light_high_constrast

gruvbox_light_low_constrast

[neiljp]

@Gopinath-Mahendiran Could you summarize the differences between the colors used in the existing gruvbox styles and those in the new versions? I'd need to look at the gruvbox variations again (ie. different contrast, etc), or potentially those of other styles, but the idea was that something like the background color could be set for different 'variants', while only needing one theme definition.

Please tidy the commits and remove extra changes that are not relevant, and get tests passing, before checking again.

It's fine to have the screenshots as examples, but I can't reproduce them with the code as it stands.

[neiljp]

I started a new topic for this in the channel - searching for either the issue or PR number should find it via the topic title.

[Gopinath-Mahendiran]

@neiljp

Differences in Gruvbox Variants:

1. Background Colors:
• High Contrast: Uses darker or lighter background colors (e.g., DARK0_HARD or LIGHT0_HARD) to create a more pronounced contrast between foreground and background elements.
• Low Contrast: Uses softer background colors (e.g., DARK1, LIGHT1) to reduce the contrast and create a more subtle appearance.
2. Foreground Colors:
• High Contrast: Employs brighter or bolder foreground colors (e.g., BRIGHT_BLUE, BRIGHT_GREEN) to make text and UI elements stand out more prominently.
• Low Contrast: Uses muted or faded colors (e.g., FADED_BLUE, FADED_GREEN) to create a more subdued and less visually striking appearance.
3. Accent Colors:
• High Contrast: Stronger accent colors (e.g., BRIGHT_RED, BRIGHT_YELLOW) are used for highlights, mentions, or important elements.
• Low Contrast: Softer accent colors (e.g., NEUTRAL_YELLOW, GRAY_244) are used to blend more seamlessly with the overall theme.
4. Grayscale Usage:
• High Contrast: Grayscale colors like LIGHT2 and DARK0_HARD are used for clear separation of UI sections.
• Low Contrast: Grayscale colors like GRAY_244 and LIGHT4 are used for a more cohesive and less jarring look.

here the different colors used in gruvbox_dark_high_constrast from gruvbox_dark

Style Name	Gruvbox Dark (Foreground, Background)	Gruvbox Dark High Contrast (Foreground, Background)
None	(Color.WHITE, Background.COLOR)	(Color.LIGHT2, Background.COLOR)
selected	(Color.WHITE, Color.DARK_BLUE)	(Color.DARK0_HARD, Color.NEUTRAL_BLUE)
msg_selected	(Color.WHITE, Color.DARK_BLUE)	(Color.DARK0_HARD, Color.NEUTRAL_BLUE)
header	(Color.DARK_CYAN, Color.DARK_BLUE)	(Color.NEUTRAL_BLUE, Color.BRIGHT_BLUE)
general_narrow	(Color.WHITE, Color.DARK_BLUE)	(Color.DARK0_HARD, Color.BRIGHT_BLUE)
general_bar	(Color.WHITE, Background.COLOR)	(Color.LIGHT2, Background.COLOR)
msg_sender	(Color.YELLOW__BOLD, Background.COLOR)	(Color.NEUTRAL_YELLOW__BOLD, Background.COLOR)
unread	(Color.DARK_BLUE, Background.COLOR)	(Color.NEUTRAL_PURPLE, Background.COLOR)
user_active	(Color.LIGHT_GREEN, Background.COLOR)	(Color.BRIGHT_GREEN, Background.COLOR)
user_idle	(Color.YELLOW, Background.COLOR)	(Color.NEUTRAL_YELLOW, Background.COLOR)
user_offline	(Color.WHITE, Background.COLOR)	(Color.LIGHT2, Background.COLOR)
user_inactive	(Color.WHITE, Background.COLOR)	(Color.LIGHT2, Background.COLOR)
user_bot	(Color.WHITE, Background.COLOR)	(Color.LIGHT2, Background.COLOR)
title	(Color.WHITE__BOLD, Background.COLOR)	(Color.LIGHT2__BOLD, Background.COLOR)
column_title	(Color.WHITE__BOLD, Background.COLOR)	(Color.LIGHT2__BOLD, Background.COLOR)
time	(Color.LIGHT_BLUE, Background.COLOR)	(Color.BRIGHT_BLUE, Background.COLOR)
bar	(Color.WHITE, Color.DARK_GRAY)	(Color.LIGHT2, Color.GRAY_244)
msg_emoji	(Color.LIGHT_MAGENTA, Background.COLOR)	(Color.NEUTRAL_PURPLE, Background.COLOR)
reaction	(Color.LIGHT_MAGENTA__BOLD, Background.COLOR)	(Color.NEUTRAL_PURPLE__BOLD, Background.COLOR)
reaction_mine	(Color.BLACK, Color.LIGHT_MAGENTA)	(Color.DARK0_HARD, Color.NEUTRAL_PURPLE)
msg_heading	(Color.LIGHT_CYAN__BOLD, Color.DARK_MAGENTA)	(Color.DARK0_HARD__BOLD, Color.BRIGHT_GREEN)
msg_math	(Color.LIGHT_GRAY, Color.DARK_GRAY)	(Color.DARK0_HARD, Color.GRAY_244)
msg_mention	(Color.LIGHT_RED__BOLD, Background.COLOR)	(Color.BRIGHT_RED__BOLD, Background.COLOR)
msg_link	(Color.LIGHT_BLUE, Background.COLOR)	(Color.BRIGHT_BLUE, Background.COLOR)
msg_link_index	(Color.LIGHT_BLUE__BOLD, Background.COLOR)	(Color.BRIGHT_BLUE__BOLD, Background.COLOR)
msg_quote	(Color.BROWN, Background.COLOR)	(Color.NEUTRAL_YELLOW, Background.COLOR)
msg_bold	(Color.WHITE__BOLD, Background.COLOR)	(Color.LIGHT2__BOLD, Background.COLOR)
msg_time	(Color.BLACK, Color.WHITE)	(Color.DARK0_HARD, Color.LIGHT2)
footer	(Color.BLACK, Color.LIGHT_GRAY)	(Color.DARK0_HARD, Color.LIGHT4)
footer_contrast	(Color.WHITE, Background.COLOR)	(Color.LIGHT2, Background.COLOR)
starred	(Color.LIGHT_RED__BOLD, Background.COLOR)	(Color.BRIGHT_RED__BOLD, Background.COLOR)
unread_count	(Color.YELLOW, Background.COLOR)	(Color.NEUTRAL_YELLOW, Background.COLOR)
starred_count	(Color.LIGHT_GRAY, Background.COLOR)	(Color.LIGHT4, Background.COLOR)
table_head	(Color.WHITE__BOLD, Background.COLOR)	(Color.LIGHT2__BOLD, Background.COLOR)
filter_results	(Color.WHITE, Color.DARK_GREEN)	(Color.DARK0_HARD, Color.BRIGHT_GREEN)
edit_topic	(Color.WHITE, Color.DARK_GRAY)	(Color.DARK0_HARD, Color.GRAY_244)
edit_tag	(Color.WHITE, Color.DARK_GRAY)	(Color.DARK0_HARD, Color.GRAY_244)
edit_author	(Color.YELLOW, Background.COLOR)	(Color.NEUTRAL_YELLOW, Background.COLOR)
edit_time	(Color.LIGHT_BLUE, Background.COLOR)	(Color.BRIGHT_BLUE, Background.COLOR)
current_user	(Color.WHITE, Background.COLOR)	(Color.LIGHT2, Background.COLOR)
muted	(Color.LIGHT_BLUE, Background.COLOR)	(Color.BRIGHT_BLUE, Background.COLOR)
popup_border	(Color.WHITE, Background.COLOR)	(Color.LIGHT2, Background.COLOR)
popup_category	(Color.LIGHT_BLUE__BOLD, Background.COLOR)	(Color.BRIGHT_BLUE__BOLD, Background.COLOR)
popup_contrast	(Color.WHITE, Color.DARK_GRAY)	(Color.DARK0_HARD, Color.GRAY_244)
popup_important	(Color.LIGHT_RED__BOLD, Background.COLOR)	(Color.BRIGHT_RED__BOLD, Background.COLOR)
widget_disabled	(Color.DARK_GRAY, Background.COLOR)	(Color.GRAY_244, Background.COLOR)
area:help	(Color.WHITE, Color.DARK_GREEN)	(Color.DARK0_HARD, Color.BRIGHT_GREEN)
area:msg	(Color.WHITE, Color.BROWN)	(Color.DARK0_HARD, Color.NEUTRAL_PURPLE)
area:stream	(Color.WHITE, Color.DARK_CYAN)	(Color.DARK0_HARD, Color.BRIGHT_BLUE)
area:error	(Color.WHITE, Color.DARK_RED)	(Color.DARK0_HARD, Color.BRIGHT_RED)
area:user	(Color.WHITE, Color.DARK_BLUE)	(Color.DARK0_HARD, Color.BRIGHT_YELLOW)
search_error	(Color.LIGHT_RED, Background.COLOR)	(Color.BRIGHT_RED, Background.COLOR)
task:success	(Color.WHITE, Color.DARK_GREEN)	(Color.DARK0_HARD, Color.BRIGHT_GREEN)
task:error	(Color.WHITE, Color.DARK_RED)	(Color.DARK0_HARD, Color.BRIGHT_RED)
task:warning	(Color.WHITE, Color.BROWN)	(Color.DARK0_HARD, Color.NEUTRAL_PURPLE)
ui_code	(Color.BLACK, Color.WHITE)	(Color.DARK0_HARD, Color.LIGHT2)

This table highlights the differences in foreground and background colors for each style between the two themes. The high-contrast theme uses bolder and more vibrant colors, while the original Gruvbox Dark theme uses more subdued tones.

[Gopinath-Mahendiran]

@neiljp now try recreating it