I compile a Project with Delphi 10.4 and then with Delphi 12
After compile in D12 the Color of
AdvPagerStyler.GlowButtonAppearance.Border.ColorDisabled is set to clLightGrey.
D10.4 can not recognize this Color and get an error "ungültiger Eigenschaftswert"
The Property is changed in the dfm file every time i compile with D12.

A similar Problem in FNCChart.Legend.Fill.Color. D12 set the Color in the .dfm File to Ghostwhite and D10.4 cannot recognize this Color.

Is there a unit i can implement so that D10.4 knows this Colors?

I cannot see this phenomenon and I can also not see any reason for our component to change its property in the DFM after a compile. A compile does not cause any DFM updates. This color is by default clWhite, both in Delphi 10.4 and Delphi 12

Can it be you have any Delphi 3rd party tool installed that interferes with property settings?

I cannot reproduce the error at the moment.
But the color palette of the component TadvOfficePagerStyler.GlowButtonAppearance.Border.ColorDisabled is completely different in D10 than in D12.

What "color palette" are you referring to?

I test it with a new Project setting a OfficePagerStyler and a FNCChart Component onto the Form.
The Standardcolor for advOfficePagerStyler.GlowButtonAppearance.Border.ColorDisabled used in OfficePagerStyler is usable in D10.

The Standard Color for FNCChart.Legend.Fill.Color ist clGhostwhite and can not be recognized in D10.
I can not open the Form in D10.

The colors in D12 are enhanced, you should not use this enhanced colors as Standard Color in a Component.
You can use Hex-Colors like in advOfficePagerStyler.GlowButtonAppearance.Border.ColorDisabled, this is working.

The default color for TTMSFNCChart.Legend.Fill is gcGhostWhite (NOT clGhostWhite)
This is an FNC defined color. It is usable in any Delphi version.
This is Delphi 10.2 for example:

Pictures what Delphi says when i put a fncChart on the Form.

The second Picture was make with Delphi12, NewProject put FNCChart Component on the Form and look at the Properties.
and the first Picture was the opening of this D12 Project

We see that Delphi 12 introduced a new color constant that doesn't exist in 10.4 and this causes this issue. I suggest you change this color in Delphi 12 to a color that does exist in 10.4 if you want to exchange the project between the two IDEs, for example to clWhite or to set the color as a hex value.

That is what i have done.
But somtimes it works and othertime the D12 Projekt change the color to the default Value or a Save is not enough and have to compile the Projekt.

The next color is
Appearance.MonochromColor and then
Labels.Fill.color than
there i cant find witch color is wrong.

Its very Timeconsuming to bring your Components to a legal color that can be used in older Delphi Versions if they are used once in D12.

The next i will try is to make the Projekt first in D10 and then use it in D12.

I understand this isn't ideal. Our components were developed long before Delphi 12 came to life, so we could not predict Embarcadero would introduce conflicting colors.
If you get color errors in old Delphi versions, set the color in Delphi 12 to a color that exists in the old Delphi version you still want to use.

To make it easier:
is it possible to load a constant-List of colors that are used in D12 and load it in the D10 project or a uses lib that define the colors.
Is there a list available.

It is perhaps an idea to copy the missing colors from Vcl.Graphics.pas in Delphi 12 and add these in a unit and have the unit installed in the IDE of Delphi 10.4.

I made a Unit with the colors Constants of the TGraphics unit from D12 an load it with my D10 Projekt.
This dont work because the Form with the FNCChart Component could not be load in D10.
This is the Project i try to open in D10:
test.zip (29.2 KB)

For this to have a chance to work, these colors should have been installed via a package in the IDE as I explained.

I also recommended to use Delphi 10.4 supported colors only if you want to use this both in Delphi 12 and Delphi 10.4

I dont know how to install the colors in a package in the IDE.
I am not a Professional Programmer.

Or you can change these colors in the FNCChart Component as default colors in Hex in one of the next Updates.

What i can do is to find the wrong colornames and then write a Delphi-Program that looks at the .dfm File and change the unknown colors.