Where do I configure the colours that are used when a printf format/variable is clicked?

Take this small method.

    protected function buildS3Path(string $table): string
    {
        return sprintf(
            '%s/%s/%s.%%06d',
            $_ENV['DB_DATABASE'],
            $this->timestamp,
            $table
        );
    }

Nothing overly complicated. Solvable with normal string concat or embedded strings.

But my question is that when I click on $_ENV['DB_DATABASE'], the first %s is highlighted. That's great! But the colours on it are a little dim.

Where do I configure the colours please?