Detailed notes about particular species and varieties.

Captain Blood
Charles Colbert
Dainty (California)
Virus Variegation
Chimaeral variegation.

Captain Blood. There are a number of Camellias which will sometimes turn purplish or even almost blue. Another variety affected is 'Dona Herzilia de Freitas Magalhaes'. It is not a consistent character, sometimes it happens, sometimes not. My own view is that temperature is the main factor. I think a very slight frosting is probably the main cause; enough to produce the colour change without killing the bloom and causing it to turn brown. It may also be the case that heavy soils favour the development of blue pigment. It is also possible that a mechanism similar to the one that makes Hydrangea flowers blue in acid soil, pink in alkaline, could have a part to play. In the case of hydranges it is the availability of Aluminium in acid soils that causes the flowers to turn blue.

Charles Colbert. One of 22 seedlings raised by Professor Waterhouse from seed produced in 1945. He had imported a plant of Camellia saluensis from Scotts of Merriot, England, in 1938 and planted it among Camellia japonica varieties. It never thrived and in 1945 flowered freely, set seed and died.
The first three flowered in 1954 and were clearly hybrids. The first to be named was C. 'E. G. Waterhouse', with formal double flowers in light pink. Other varieties from the 22 include 'Lady Gowrie', 'Bowen Bryant', 'Margaret Waterhouse', 'Shocking Pink', 'Crinkles', 'Ellamine', 'Clarrie Fawcett' and 'Farfalla'.
Dr Brian Doak, a hybridizer from New Zealand, obtained a cutting from E. G. Waterhouse's C. saluensis and crossed it with C. reticulata 'Captain Rawes to produce 'Phyl Doak', 'Fair Lass' and 'Barbara Clark'.

Dainty (California). This was labelled 'Dainty', but seems to match the description in the Camellia Register for 'Dainty' (California). The name 'Dainty had already been used so should not have been applied to this 'Tricolor' sport. Raised by E. H. Carter of Monterey Park, California, it is, like most bicolors, unstable and prone to producing blooms of various colour patterns. The register describes it as "blush white striped red with fringed and ruffled petals", so presumably the top two pictures show it as it was intended to be.

Virus variegation. Viruses can cause destruction of chlorophyll in leaves and colour pigment in flowers. When it affects leaves it causes areas of the leaf to become bleached in appearance to the detriment of both appearance and growth.
When flowers are affected it results in fuzzy edged, irregular white blotching of the petals. The amount of white and the number of flowers affected is very variable. It is often striking; whether it is attractive is a matter of personal taste.
The virus responsible can be transmitted from plant to plant deliberately or accidentally. Grafting un-infected scions onto infected stocks will cause virus infection, as will root grafting between adjacent plants. It may be possible to transmit virus with propagation tools that have been used on infected plants and it is possible that sap sucking pests such as aphids could also be responsible.
Once a plant is infected with virus there is no easy way to remove or kill it.
It is not accurate to describe a virus variegated form as a sport. A sport is a different form which arises by genetic mutation.

Chimaeral variegation. Many varieties of camellias have flowers of more than one colour, typically red, pink and white. Most frequently there is a pattern of stripes or streaks more or less radiating from the centre of the flower. The edges of the different areas of colour are fairly sharp, as distinct from the fuzziness of virus variegation.
This type of variegation is chimaeral (chimeral) and is due to the presence of two distinct genotypes within the tissue that makes up the petals.
The most common type of chimaera encountered in horticulture is that of foliar variegation. A mutation occurs in the growing point of the shoot, leading to the production of tissue lacking chlorophyll. The growing point tends to produce cells in layers which remain discreet and give rise to different parts of the shoot. If the whole of a layer lacks the ability to produce chlorophyll then the leaves will typically have a white or yellow margin or centre. This type of chimaera is reasonably stable and described as periclinal.
There are several camellia varieties which produce blooms which are bicoloured in a comparable way. Typically they might be pink with a narrow white margin, such as 'Hikarugenji', 'Jean Clere' or 'Yours Truly'. 'Margaret Davis' reverses the situation, with pink pigment restricted to the edge of the petals.
Pigmentation is not the only mutation that can be chimaeral; it seems likely that the fimbriated petals of 'Fred Sander' indicate a periclinal mutation of its parent 'Lady de Saumerez'.
In a great many camellias the organisation of the mutated tissue is not periclinal but pretty much random. In animals a type of chimaera called mosaicism is recognized. In plants mosaic variegation, especially of leaves, will be indicative of viral infection. I'm no geneticist but I believe the type of flower colour variegation seen in a variety like 'Lavinia Maggi' or 'Little Bit' is a chimaeral mosaic.