Chemical Colors

Chemical colors make up the larger portion of available color pigments. Certain chemicals are combined and a reaction takes place, causing a pigment of a definite color to be thrown off. This process is known as precipitation. The chemical reaction that takes place sometimes carries over into the paint materials and causes the color pigments to fade or react with surrounding chemicals or ultra-violet rays (sunlight).

Present day chemical color is stable and can be used in a wide variety of environments.

Chemical colors are the Blues, Yellows, Greens, Reds, and Blacks.

1. Phthalocyanine Blue (Thalo Blue)-fig.(1)

A pure clear blue that is not affected by sunlight or alkalinity. The most widely used blue for tinting paints and coatings.
Other blues like Cobalt Blue, Prussian Blue and Ultramarine Blue can be found in artists' colors but are not readily available as colorants in architectural paints.

2. Hansa Yellow (Light Yellow)-fig.(2)

A very light yellow with poor tinting strength.
Has a slight greenish cast when used to make an off-white.
This pigment is slightly transparent in paints producing poor "hiding" power .
A strong yellow made from Basic Lead Chromatewas used historically but now cannot be used for architectural coatings because of the lead content.

3. Light Green-fig.(3)

Yellow and blue make green.
When the colors are mixed mechanically, they are liable to separate and break down prematurely.
When yellow and blue are mixed chemically, the results are a stable blend.
Light green has a large amount of light yellow with a small amount of blue.

4. Phthalocyanine Green (Thalo Green)-fig.(4)

A very dark, bluish green with strong tinting strength.
Other greens like medium green and Chromium Oxide are not commonly found as colorants for architectural paints.

Many reds have been produced over time. Many are still available in artists' paints and industrial coatings. Names like Venetian Red, Rose Pink, Indian Red, Tuscan Red, Chinese Vermillion and Permanent Red are just a few. There are three reds that are commonly used to tint paint:

5. Napthol Red-fig.(5)

A red that is slightly orange. Has fair tinting strength and produces a clear, bright color .

6. Orange-fig.(6)

Red with yellow added to produce a strong, yellow colorant. Used with white to produce peach tones.

7. Interior Red-fig.(7)

A red that is slightly orange.
Has fair tinting strength and produces a clear, bright color .

8. Lamp Black-fig.(8)

Can be made with substances that burn with a smoky flame.
The unburned portion of coal tar oils (carbon) is used in making Lamp Black.
The pigment is slightly oily which can retard the drying of some paints.
A very strong pigment that should be used with care.

Although only 14 color pigment colors have been identified, there are two more that are used by the paint manufacturer and distributor to produce custom colors.

9. Titanium White-fig.(9)

A concentrated white pigment used in conjunction with other color pigments.

10. Purple-fig.(10)

A chemically produced purple that is used instead of mixing the available blue and red color pigments.
A bright, clear purple cannot be produced with blue and red because the red has some yellow in it while the blue also may have a trace of green. The colors will gray themselves off.