I would like to see a compact UI theme option for email inbox.

I've seen this implemented on slack and also on gmail. it would be nice to be able to choose from different colour schemes in the settings page. I like how you've implemented a dark theme in the beta, but we could have some more fun colour options e.g. terminal colours (black and lime green), ultraviolet (violet and black/white), etc.

Add optional color based themes or least keep the basic one from the current proton mail theme.

If you mean the bright white background in the mail body, I agree. It is a huge contrast with the rest of the screen. I would like to be able to grey it down so it isn't so bright.

Suggestion: Bring Animated Background Themes

Agreed, I thought it was only me. It really needs a face lift in the aesthetics category. It is rather drab.

In the dark I would like a dark theme to be completely dark with only the text, lines and symbols visable.

I am surprised this topic was posted in 2016 and still is not a priority. I really love the product but I just can"t work with depressive black color and only 1 option available to choose from themes. I am not a programmer myself, so don't want to bother about those css codes. Can you make the flexibility to a broader audience and include more feminine like pastel colour or at least lighter themes too? Thank you

I am surprised this topic was posted in 2015 and still is not a priority. I really love the product but I just can"t work with depressive black color and only 1 option available to choose from themes. I am not a programmer myself, so don't want to bother about those css codes. Can you make the flexibility to a broader audience?

I really like the beta features (calendar), but would like to be able to keep using the standard (non-beta) email theme.

THE PROTONMAIL SERVICES WOULD IMPROVE IF YOU ADD MORE
USER FRIENDLY THEMES. PROTONMAIL IS A VERY SECURE EMAIL SERVICE NO DOUBT , BUT THE SERVICES WOULD IMPROVE IF YOU GIVE MORE BEAUTIFUL THEMES

I suggest editing the title of this idea to "Custom theme saving and sharing", what do you think @HHH?

Great idea indeed, a community area where people could share the themes they crafted would be a nice feature, with the ability to browse them directly from the appearance section of the Protonmail settings. Here's below the one I use at the moment in case you want to give it a try :-) (pink raw mode). Also, the area for typing custom CSS is quite thin, a larger width would be handy, together with the ability to use more human-friendly syntaxes than pure CSS, e.g. Stylus.

.main {
margin-right: 0;
}

.content {
background-image: none;
background-color: #603259;
}

.item-container {
background: #eabde7;
}

.item-container.active, .item-is-selected {
background: rgba(226, 184, 238, 0.5);
}

.toolbar {
background: #7b5a7b;
border-radius: 0;
}

.pm-button--error, .pm-button--error.pm-button--info, .pm-button--error.pm-button--redborder, .pm-button--primary, .pm-button--primary.pm-button--info, .pm-button--primary.pm-button--redborder, .pm-button--warning, .pm-button--warning.pm-button--info, .pm-button--warning.pm-button--redborder, .pm-button-blue, .pm-button-blue.pm-button--info, .pm-button-blue.pm-button--redborder, .pm-button.pm-button--error, .pm-button.pm-button--primary, .pm-button.pm-button--warning, .pm-button.pm-button-blue {
background-color: #8a1d79;
border: 1px solid #7209a2;
}

.view-column-detail {
background: #c297bf;
}

#conversation-view .message .frame {
background: white;
}

.message-attachments {
background: #f5f5f5;
}

.items-column-list, .items-column-list--mobile, .view-column-detail {
scrollbar-width: none;
}

.navigationItem-title.flex-item-fluid {
display: none;
}

.sidebar {
max-width: 8rem;
}

#tour-label-settings {
display: none;
}

.menuLabel-title.ellipsis.flex-item-fluid {
display: none;
}

.navigation__icon {
fill: var(--fillcolor-icons, #ddd);
}

.logo-container {
display: none;
}
.searchbox-container {
margin-left: 1em;
}

.dropDown-logout-displayName {
display: none !important;
}
.dropDown-logout-email {
display: none !important;
}

.mr1.flex-item-noshrink {
display: none;
}
button[action-compose-type="new"] span {
display: none;
}

button[action-compose-type="new"]::after {
content: "C";
}

.searchbox-container {
width: 20%;
}

#conversation-view header {
color: #fff;
}

.pm-select-all .pm-checkbox-fakecheck, .pm-select-all .pm-radio-fakeradio {
border: none;
background-color: white;
}
.pm-checkbox-fakecheck, .pm-radio-fakeradio {
border-radius: 0;
}

.item-icon {
display: none;
}

.mr1 {
margin-right: 0.6em;
}

.item-container, .item-container-row {
border-bottom: 1px solid var(--bordercolor-input,#d0a2cb);
}
.conversation.marked::before {
background-color: #881a86;
}

.starbutton {
display: none;
}

.mauto.conversation-icon-attachment {
display: none;
}

Cheers and thumbs up

I know there is an option to add CSS and make the email look just like we want it to be. But most of the people are not tech-savvy, yet want to use Proton mail. Can you add more themes out of the box?

I seen it on yahoo mail and I wish it was on ProtonMail.

More Yahoo-like color options. Great service by the way. Looks great and meshes with my science fiction blog and is so stable

I second this.

You may want to simply add your votes and comments to this already well-established feedback suggestion:

https://protonmail.uservoice.com/forums/284483-feedback/suggestions/13005834-dark-theme-would-be-ideal#comments

I need more additional themes.
See yahoo mail.
Thank you!

Look in your Settings --> Appearance (where you tried the Classic Theme). Notice how there's a lot of CSS in the Custom Theme text box. Just click "Reset Theme".

The OP's probably figured this out, but just thought I'd share for anyone else who stumbles upon this issue.