Concrete by Day, Nero by Night: A Practical Light/Dark Style Pair for Delphi FMX

 One of the nice things about Delphi FMX is that you can change the look of an application without rewriting the application.

That sounds simple.

In practice, finding two styles that work well together can take some trial and error.

For Debt Blaster, I wanted a clean light theme and a clean dark theme. I did not want the application to feel like two completely different programs depending on the selected theme. I wanted the light and dark versions to feel related.

That is where the Concrete and Nero FMX styles came in.

The GetIt Package Manager

Both styles are available through the Delphi GetIt Package Manager.

In GetIt, I installed:

FMX Style - Concrete 1.0
FMX Style - Nero 1.0

The style files I am using are:

Concrete_Win.style
Concrete_macOS.style
Nero_Win.style
Nero_macOS.style

That gives me a light and dark style for both Windows and macOS.

Concrete and Nero styles installed from Delphi's GetIt Package Manager

Concrete for the Light Theme

The Concrete style gives the application a clean light appearance without making it look too flat or unfinished.

It works well for traditional business software because the controls are easy to read, the grid lines are clear, and the interface still feels like a desktop application.

For Debt Blaster, that matters.

This is not a game. It is not a flashy demo. It is software people use to enter real debt information, compare payoff plans, and make decisions.

The user interface needs to stay out of the way.

Concrete does a good job of that.

Debt Blaster using the Concrete FMX style on Windows.

Nero for the Dark Theme

The Nero style is a strong companion to Concrete.

It gives the application a dark theme without changing the basic structure of the screen. The same grids, menus, fields, buttons, and panels are still there. They just shift into a darker working environment.

That is what I like about this pairing.

Concrete and Nero feel like they belong to the same family.

One works well when I want a light application. The other works well when I want a dark application.

Debt Blaster using the Nero FMX style on Windows

Why I Like This Pair

The big win is consistency.

When I switch between Concrete and Nero, the application does not feel redesigned. It feels restyled.

That distinction matters.

A good style should support the application. It should not make the user stop and think, "What happened to the program?"

Concrete and Nero give me:

Light theme: Concrete
Dark theme:  Nero
Windows:     platform-specific style files
macOS:       platform-specific style files

That gives me a clean path for supporting both Windows and macOS without pretending one style file should handle every platform perfectly.

One Practical Lesson

FMX is cross-platform, but that does not mean every visual decision automatically behaves the same way on every platform.

For this reason, I prefer using the platform-specific style files:

Concrete_Win.style
Concrete_macOS.style
Nero_Win.style
Nero_macOS.style

That keeps the intent clear.

Windows gets the Windows style file.

macOS gets the macOS style file.

That is easier to understand, easier to debug, and easier to explain six months from now when I come back to the code and wonder what I was thinking.

Final Thought

If you are building a Delphi FMX application and want a clean light/dark style combination, Concrete and Nero are worth a look.

They are easy to install from GetIt, they work nicely together, and they give an FMX desktop application a more finished appearance with very little effort.

For me, Concrete and Nero are not just two random styles.

They are a practical pair:

Concrete by day.
Nero by night.

And for Debt Blaster, that pairing fits very nicely.

Enjoy
Semper Fi
Gunny Mike
https://zilchworks.com
https://debtblaster.com