The colour-savvy designer, who previously had her own fashion label, knew exactly what she wanted: a polish free from a long list of nasty chemicals.
Formaldehyde, toluene, DBP, camphor, formaldehyde resin, xylene, parabens, fragrances, phthalates, sulfates, palm oil, petrochemicals and animal-derived or tested ingredients - such as the fish scales and crushed beetles used for their textured, iridescent effect - are banned.
Ross spent a year developing an initial range of six colours, then quickly discovered that nail polish was a fair deal more lucrative than silver jewellery, which had been hit by a glut of cheap imports from Bali.
"We tripled our turnover in three months, so I knew we were onto a winner," she told news.com.au.
Initially selling through six stores that had previously stocked her jewellery, she quickly grew Kester Black's stockist list and took it to a design market.
"I had a look book with photos I'd taken myself at home, which I sent to stores, and people responded," Ross said.
The appeal of the range, she believes, is its positioning, which she took "out of the cosmetic space and into a design and fashion context".
Think Panetone, rather than Maybelline, Cover Girl, Chanel or Dior. Priced at $20 a pop, the polishes are less expensive than a high-fashion brand, but costlier than a made-in-China cheapie - which she emphasised could be full of dangerous chemicals, due to lax importation laws.
Kester Black also donates $1 from every online order to one of its favoured charities, which help asylum seekers and disadvantaged schoolgirls in India.
Ms Ross decided the time had come to move the operation out of her bedroom three years ago.
"I started getting interns, they came and worked out of my bedroom and I thought 'this is weird'," she laughed.
A more serious consideration was the fact that, she learned, her product insurance would be voided if things went awry, with her rental agreement prohibiting the storage of flammables.
Now Kester Black has a team of seven staff working from its head office in Collingwood and remotely, with distributors all over the world.
Its wares are sold in Italy, Switzerland, Austria, Germany the Netherlands and Belgium, with the United Kingdom next on the horizon.
Kester Black is in the process of drumming up investors to bankroll a $30 million, five-year plan to pursue an aggressive growth strategy.
Ms Ross wants to invest in product development and marketing to expand the company's reach in export markets, including the United States - a notoriously challenging place to do business in the cosmetics space, with competitors like Sephora to contend with.
"We'll do four international trade shows next year, and once we have a full line developed we will launch a big marketing and PR campaign in those countries at the end of this year," she said.
The biggest challenge, she said, was the crippling cost of international postage.
"International freight is a killer to our business - it's $60 to send a $20 nail polish," she said.
Kester Black offers free shipping for orders over $100, meaning the business has to wear the cost.
"It's much easier to have a distributor," Ms Ross said.
The former fashion designer said that while working in clothing and cosmetics might seem glamorous, the reality was a lot less exciting.
"It looks and sounds fun, but it's a lot of working with lawyers and accountants, forecasting sales, looking at cashflow and compliance," she said.
Selling a product like nail polish in a global market came with its fair share of complications, she said, citing the two months it took her to obtain an international dangerous goods license.
"I had to learn how to ship explosives and write ingredient lists to comply with the laws of each jurisdiction - it changes in every country," Ms Ross said.
