Tomatoes which are characteristically red when ripe, but are not overripe or soft, may be classified for maturity as follows:
(a) Turning, when at least some part of the surface of the tomato, but less than one-half of the surface in the aggregate, is covered with pink color.
(b) Pink, when the tomato shows from one-half to three-fourths of the surface in the aggregate covered with pink or red color.
(c) Hard ripe, when the tomato shows three-fourths or more of the surface in the aggregate covered with pink or red color.
(d) Firm ripe, when the tomato shows three-fourths or more of the surface in the aggregate covered with red color characteristic of reasonably well ripened tomatoes.
(e) Incident to proper maturity determination, not more than a total of 10 percent, by count, of the tomatoes in any lot may fail to meet the maturity specified: Provided, That not more than 5 percent shall be allowed for tomatoes which are immature or are overripe or soft.