Oh it works. Thank you.

By the way, i cannot change any color in the presets --> Custom Style. I set the new color code and save it but still looks the same.

After change the color code, i got this errors on frontend editor view now:

Deprecated: Non-canonical cast (boolean) is deprecated, use the (bool) cast instead in /home1/trainin9/public_html/test/plugins/system/helixultimate/html/layouts/libraries/cms/html/bootstrap.php on line 339

Deprecated: Non-canonical cast (boolean) is deprecated, use the (bool) cast instead in /home1/trainin9/public_html/test/plugins/system/helixultimate/html/layouts/libraries/cms/html/bootstrap.php on line 340

Deprecated: Non-canonical cast (boolean) is deprecated, use the (bool) cast instead in /home1/trainin9/public_html/test/plugins/system/helixultimate/html/layouts/libraries/cms/html/bootstrap.php on line 440

How do i solve this?

test.trainingdynamics.sg

Probably you set a too high PHP 8 version.

Right now you cannot use PHP 8.5 with that template. Please switch to PHP 8.3 for now, and wait for next Helix Ultimate plugin update, it should be in next weeks.

But before , maybe try that file, download & unzip: bootstrap_UNZIP_ME.zip

Then using FTP or File Manager override file here:
plugins/system/helixultimate/html/layouts/libraries/cms/html/

Thank you. the errors go away after changing to PHP 8.3.

But i still cannot change the colors for the text and background in the templates options > Presets > custom style (enabled)

I saved the hex code but nothing change.

I also try to change the hex code in templates options > Presets > Presets 1 but also nothing change.

Please let me know how can i change the color.

Please create separate topic for that new question, with information what colors you want to use.