I'm having a problem where when I set "Titles inside + Masonry Layout" for Portfolio Settings/Portfolio Layout/Thumbnail Options, the color I choose for "Hover color background for this type" isn't being displayed when I look at my portfolio page. Neither the like icon nor the hover effect background is displayed in the color I set in said portfolio control panel.

However, when I choose "Visible Titles" or "Titles Inside" the color that I set in "Hover color background for this type" is being displayed correctly on the live portfolio page.

I determined the variable "$hover_color" isn't being set correctly for the portfolio setting in question.
This is for the element: "#portfolio-2.portfolio-holder .item-box .thumb .hover-state". It always reverts back to #ebebeb for me in "Titles inside + Masonry Layout".

The transparency setting in Portfolio Settings/Portfolio Layout/Portfolio Layout Type works on the other hand.

Could you confirm this working correctly on your end?
I can't rule out whether I set a custom CSS at some point in time, but I searched basically everywhere in the settings of my Wordpress installation and in the back-end but can't find anything that I might have forgotten to take out. I already disabled any custom CSS I could. The color still doesn't stick.

Edit: I just tried to create a separate custom portfolio page with "Portfolio Page" as template and none of the preferences from "Parameters and Options" in the "Edit Page" window seem to stick. I can set "Page Options" and those are applied, but nothing from "Parameters and Options".

What am I missing?

Stats:
Kalium child theme with:
Kalium 2.0.6.1
php 7.0.13
mysql 5.7.16
wordpress 4.7.3

Art, it doesn't look like I have the permission to give other persons administrative access to this site due to security concerns.
Is there anything else I can do? (EDIT: please see the end of this message for a (possible) solution I found while researching my issue.)

In the meantime I have uploaded and set-up a test Wordpress installation with dummy images and set up a some portfolio items and it is all working as intended there. Next I deleted and reinstalled the theme on the main site, deleted and reinstalled the child-theme, checked the functions.php, removed all custom css, deactivated and/or deinstalled all plug-ins except those necessary for Kalium to function... still the same malfunction.
I can see in the generated live html that with the 'problematic' portfolio there are css styles overriding the correctly set css, effectively blocking the correct styling and I can't figure out why and at which point the faulty css is injected:

html excerpt of the test installation portfolio which is working as intended:

<div class="page-container">
<div class="row">
<div id="portfolio-2" class="portfolio-holder portfolio-type-2 is-masonry-layout sort-by-js portfolio-loop-custom-item-spacing" style="position: relative; height: 251.75px;">
<div class="portfolio-item portfolio-item-type-1 has-padding w4 post-35 portfolio type-portfolio status-publish has-post-thumbnail hentry portfolio_category-zufall" data-portfolio-item-id="35" data-terms="zufall" style="position: absolute; left: 0px; top: 0px;">
<div class="item-box-container">
<div class="item-box wow fadeInLab animated" style="visibility: visible; animation-name: fadeInLab;">
<div class="thumb">
<div class="hover-state padding hover-eff-fade-slide position-bottom-left hover-distanced hover-style-primary opacity-yes">

html of the malfunctioning portfolio items in my main installation:

<div class="page-container">
<div class="row">
<div id="portfolio-2" class="portfolio-holder portfolio-type-2 is-masonry-layout sort-by-js portfolio-loop-custom-item-spacing">
<div class="portfolio-item portfolio-item-type-5 has-padding w4 post-6898 portfolio type-portfolio status-publish has-post-thumbnail hentry portfolio_category-street portfolio_tag-streetphotography" data-portfolio-item-id="6898" data-terms="street">
<style>#portfolio-2 .post-6898 .item-box .thumb .hover-state {
background-color: #ebebeb !important;
}</style><style>#portfolio-2 .post-6898 .item-box .thumb .hover-state .likes .like-btn > * {
color: #ebebeb !important;
}</style>
<div class="item-box-container">
<div class="item-box wow fadeInLab">
<div class="thumb">
<div class="hover-state padding hover-eff-fade-slide position-bottom-left hover-distanced hover-style-primary opacity-yes">

Notice the additional style elements that override the hover color.

For both of these portfolios the injected styling after the head section of the html is the same and you can see the correct colors being set (#8224e3 and #bf62ea) as per the portfolio options in Laborator settings.
This is it for both installations on the portfolio page:

<script type="text/javascript">
	var headerOptions = headerOptions || {};
	jQuery.extend( headerOptions, {"stickyHeader":{"type":"autohide","wrapper":".wrapper","container":".main-header","logoContainer":".header-logo","spacer":true,"initialOffset":0,"debugMode":false,"animateDuration":true,"breakpoints":{"desktop":[992,null],"tablet":[768,992],"mobile":[null,768]},"skin":{"classes":["menu-skin-main","menu-skin-dark","menu-skin-light"],"current":"menu-skin-main","active":"menu-skin-main"},"scenes":{"paddingSceneOptions":{"scene":[],"tween":{"easing":"Sine.easeInOut","css":{"paddingTop":"10px","paddingBottom":"10px"}}},"backgroundSceneOptions":{"scene":[],"tween":{"easing":"Sine.easeInOut","css":{"backgroundColor":"rgba(255,255,255,0)"}}},"logoSceneOptions":{"scene":[],"tween":{"easing":"Sine.easeInOut","css":[]},"logo":{"src":"","width":30,"height":28}}},"autohide":{"duration":0.3,"easing":"Sine.easeInOut","css":{"autoAlpha":0}}},"sectionLogoSwitch":[]} );
</script>
<style>#portfolio-2.portfolio-holder .item-box .photo .on-hover {
background-color: #8224e3 !important;
}</style><style>#portfolio-2.portfolio-holder .item-box .thumb .hover-state {
background-color: #bf62ea !important;
}</style><style>#portfolio-2.portfolio-holder .item-box .thumb .hover-state .likes .like-btn > * {
color: #bf62ea !important;
}</style><style>#portfolio-2-container.portfolio-container-and-title.full-width-portfolio {
padding-left: 0;
 padding-right: 0;
}</style><style>#portfolio-2-container.portfolio-container-and-title.full-width-portfolio .portfolio-holder {
margin-left: 20px;
 margin-right: 20px;
}</style><style>#portfolio-2-container.portfolio-container-and-title > .row {
margin-left: -10px;
 margin-right: -10px;
}</style><style>.page-container > .row {
margin: 0 -10px
}</style><style>.portfolio-holder.portfolio-loop-custom-item-spacing [data-portfolio-item-id] {
padding: 10px;
}</style><style>.portfolio-holder .portfolio-item.masonry-portfolio-item .masonry-box .masonry-thumb {
margin: 10px;
}</style>

EDIT:
What I did now was go into the mysql table and hunt for the background color for post-6898 as an example and lo and behold all my portfolio items have wp_postmeta entries for

meta_key: custom_hover_background_color
meta_value: #ebebeb

Since I have a backup of my (supposed erroneous) database I went ahead and deleted one of the meta entries for a portfolio item and now this item works as intended. The additional style elements are gone from the html!
Which is a good thing, but also makes me worry about what additional meta entries could be in there which are unnecessary or even interfering with normal operations in my database. Would you advise to delete above mentioned meta entries to ensure the hover color to be working as intended with Kalium?
How can I verify that my database is in working order? How can I find entries that are either defunct, 'harmful' or unnecessary?

Thank you for your help and patience reading this.
Peter

Art,

thank you for getting back to me.

I deleted all optional plug-ins and all custom css. No change.
Then I copied over the database and installation to another domain to create a safe environment for third parties, started to delete all personal information and sensitive data...
Then I took a step back and created a new portfolio item on the live site and it is working as intended.
This made me wonder...
I took another look at the Parameters and Options part of the portfolio item page and realized under Other Settings there is a Custom Hover Background Color option, which was set to the color in question. I deleted (emptied) that color and now the item hover is working as intended on the portfolio archive page.

Bottom line: getting a project passed on from another team member is a delicate task and it is easy to overlook things.

Thank you for your help and please excuse me for maybe not being clear enough in my problem description to give you the opportunity to advise me to check for this color option in the according setting in Parameters and Options.

Happy holidays (if you have them).
Thanks,
Peter