I see purple every day in my work at Color Accounting, as it is the symbol for profit in our BaSIS Framework. Purple points to Profit!
Yellow for Liabilities, Equity & Income, the source of all funds, without which businesses can't exist. Rather like the sun, the source of all our energy.
And in the green area of our framework, the business puts the funding to work, as Assets & Expenses. Just as plants photosynthesize sunlight in their leaves to grow and thrive.
Yes, colors have always been symbolic. Which is why purple has also trumpeted the presence of royalty for eons.
Best regards, Peter