NEW YORK (TheStreet) -- We've all heard of blue-chip stocks, but what about "purple-chip" stocks? John Schwinghamer, author of "Purple Chips," explained the concept to TheStreet's Gregg Greenberg.

Purple-chips, according to Schwinghamer, are the royalty of blue-chip stocks. Based on their increasing and consistent earnings power, they make better investments than your average blue-chip company.

C.H. Robinson ( CHRW) was the first on his list. Although the company may not seem very exciting to some, its ability to hold up in a sluggish economy proves valuable.

He explained that during the financial crisis in 2008, the company was able to not only keep earnings per share afloat, but actually increase it through the troubling times.

Oracle ( ORCL) also made the list, despite its recent earnings hiccups. Despite the short-term turmoil, the company has a long-lasting ability to provide solid earnings results, Schwinghamer said.

While we might not see the behind-the-scenes action between merchants and credit-card companies, that doesn't mean there isn't there a business there.That environment is exactly where Global Payments ( GPN) thrives, and it should only continue grow as we keep moving towards a cashless society, he added.

With the harsh selloff in April, Schwinghamer believes Cognizant Technology Solutions ( CTSH) is a buy based on valuation. The company is a consistent earnings grower and when valuations get this low, it usually indicates that all of the bad news is baked in, making upside surprises more likely.

When looking for his purple-chip selection, Schwinghamer said he searches for stocks with a market cap of at least $1 billion, seven years of earnings growth, and relatively "predictable" earnings results.

-- Written by Bret Kenwell in Petoskey, Mich.

Bret Kenwell currently writes, blogs and also contributes to Rocco Pendola's Weekly Options Newsletter. Focuses on short- to intermediate-term trading opportunities that can be exposed via options. He prefers to use debit trades on momentum setups and credit trades on support/resistance setups. He also focuses on building long-term wealth by searching for consistent, quality dividend paying companies and long-term growth companies. He considers himself the surfer, not the wave, in relation to the market and himself. He has no allegiance to either the bull side or the bear side.

More from Opinion

Attention 60 Minutes: Google Isn't the Only Big-Tech Monopoly

Attention 60 Minutes: Google Isn't the Only Big-Tech Monopoly

Apple Buys Tesla? Amazon Buys Sears? 3 Dream Mergers That Just Make Sense

Apple Buys Tesla? Amazon Buys Sears? 3 Dream Mergers That Just Make Sense

Amazon's Assault on Grocery Stores Will Have a Profound Impact on Many

Amazon's Assault on Grocery Stores Will Have a Profound Impact on Many

It's Dumb to Think There Aren't Already Monopolies in Big Tech

It's Dumb to Think There Aren't Already Monopolies in Big Tech

Google's EU Battles Are Hardly a Reason to Panic

Google's EU Battles Are Hardly a Reason to Panic