Missing related lists when using custom theme

[Philip Hulshize]

It seems when following the directions to create a custom theme, that ServiceNow loses the ability to display related lists.

I created a custom core default theme which I made at a higher order than Colors - which I also used as core. This theme works fine, and on requested items, sctasks, changes I see the related lists.

If I enable Dark Theme, and use the ootb dark theme, I also can see the related lists.

However, if I create a color theme as a variant using the method of using the Color Generator page, copying the json, and pasting into a variant theme - I get no related lists on many forms.

It seems there is something in the ootb themes that is not being added when you create your own themes.

[Adria Martinez · Accepted solution]

Just adding the line " "isDark": "true"," to the UX Style JSON, it works.

[Philip Hulshize]

Well Adria, you've found it! Seems the culprit is the  sys_property glide.ui.polaris.dark_themes_enabled. If you set that to false, the related lists come back. If you want the dark theme, you apparently have to declare if your style is dark or not.  I replaced lines 1-3 in the json. These were:
{
"properties":
{

I replaced them with the following:
{
"isDark": "false",
"base": {

This matches up with what is at the beginning of the Dark theme. I set it to false for any of my themes that were not supposed to be dark. I am not sure what else this might affect, so I am still testing, but, as it is easy to revert, I am going to move forward with this as a solution.

[YummyAmericano]

"isDark": "true" or "false" will solve the missing related lists. However, "true" or "false" will gives you different vibes. This is what I found so far.

"isDark": "false", - this line of code will not eliminate the shadow box.
"isDark": "true", - this line of code it will eliminate the shadow box. 
Please see the screenshot (isDark is TRUE vs FALSE).

[Shuntrell]

I am having the same issue.  I reached out to SNOW support and they said "I apologize for any inconvenience, however the support team is a break-fix organization for out of the box components. Therefore, I will not be able to dig too much into this customized theme."

[Philip Hulshize]

See Adria's response, and my added findings. I believe this is the solution.