Hello @miicat and welcome!
Looks nice, thanks :-)

Quick review: the text for the headers of the logs lacks contrast:

Hi @Alkarex,
Thanks :3

Good testing. I will fix that and optimize the SVGs once I know how to

I would prefer to use filter in CSS instead of new icon files

Could you please try this?

.icon, 
.header > .item.title .logo {
  filter: invert(89%) sepia(100%) saturate(214%) hue-rotate(287deg) brightness(104%) contrast(102%)
}

This page helps to get a good starting point to create filter parameters:
https://codepen.io/sosuke/pen/Pjoqqp

The tool to optimize SVG files: https://jakearchibald.github.io/svgomg/

I fixed the bug with the log's navigation buttons and optimized the SVGs

I looked into the filter, but figured it wouldn't be that easy as some images have different colors (and also, those may change in the future)

Let me know, if you find anything else that needs to be fixed :3

Icons:
I would prefer to have a transparent background instead of a black background.
(f.e. p/themes/Dark-pink/icons/favicon.svg p/themes/Dark-pink/icons/favicon-96-padding.png p/themes/Dark-pink/icons/favicon-256.png etc)

p/themes/Dark-pink/icons/FreshRSS-logo.svg: I would prefer to use CSS filter. Filter are used in all other themes to color the FreshRSS icon.

In general I want to point that most themes use CSS filters to color the icons. It reduces the effort to maintain the themes. For example: see "Flat design" theme. The grey icons are made white with CSS filters, except the star and red envelop icon:

#toggle-unread .icon, #toggle-starred .icon {
filter: none;
}

From point of theme maintaining, I would suggest:

• use CSS filters instead of new icons
• copy dark.css into this new theme
• add pinkdark.css and add here only the needed lines to color it.

Somehow I do not have a pink FreshRSS logo.
And the dropdown arrow needs some other color (please check: in theme "dark" there is a lighter border around the dropdown that is removed/not visible in this pink theme)

@math-GH I'm not ready yet, I will let you know, when you can take another look

@math-GH You can take another look now :3

Good for you @math-GH ?

I have tested a bit on my side and it looks fine. Let's merge to potentially gather a bit more feedback :-)

I have been using the theme daily and haven't found any new bugs