When it comes to Celeste Bianchi it becomes difficult to center the problem.
Yes because unlike the “Red Ferrari” there are no codes, there is no Pantone or RAL that encodes it, because there is not only a Celeste, but that color has changed over the years. Even in the same periods you will find bikes of different models with different tones, tones that have been repeated, have acquired pearly, shiny finishes, and finally have evolved with the transition from paints to lead to those of solvents (toxic) then to non-toxic solvents, water etc.
So with variations that it is very difficult to reproduce faithfully without a search that allows to create a database of dyes, a series of samples and comparisons with a number of preserved bicycles.
Already starting from preserved bikes is not simple and obvious because a frame may have been repainted at the end of “career” (all “Squadra Corse” frames were refurbished before the end-of-season sale) or may have been “renewed” by the house, or had undergone a paintwork due to oxidation or neglect problems.
Starting from preserved frames it is necessary to look for parts that have not suffered the effect of the weather, protected perhaps under cable ties, under canvas tape, inside the steering tube etc.
From here you need to read the color values with a color-meter, produce samples that give the same tones at the reading, compare them with the frame or the starting parts to check if the response to light is the same.
Now, from those samples you can start to reproduce the color tone at a color factory with dyemeter.
But if I have the color tone I’m done? No, because there are different brands of paints and different standards, so the same tint has different codes and you can not start from a code but you need to read a sample and reproduce it. Even giving the RGB or CMYK values of the sample does not allow you to reproduce it without being able to read it because it is not data that can be inserted into all color reproduction systems.
For this reason, after a research that continues we can give the RSC members a sample of color from which to start to redo the tint and restore their bike.
However, there are a few aspects to consider:
-your bike may have signs, wear, rust, yellowing or discolouring due to sun, weather, oils, so the “standard” tint is fine for a full restoration, for a better retouching light adjacent parts and starting from those;
-You don’t always need to repaint, a thousand times better to preserve a frame protecting the intact parts and cleaning the ruined ones.
In addition to the paint it is necessary to consider that it is not easy to find correct decals, impossible or almost if these are cup. So the best paint job could be ruined by too thick stickers or visible reproductions.
Finally, too many painters tend to give excessive gloss over paint. For some models it is impossible because the original lead technology did not provide additional layers, the paint was very shiny and the decals were applied with cups that protected them without further finishing.
To complicate matters again, we consider that in some periods Bianchi used decals under gloss, over gloss, written made in paint mixed with decals over gloss, metallic paints, opaque paints.
Later we’ll see every aspect in more detail, but just to dispel a couple of myths set up by someone too lazy to do a couple of researches: RAL 6019 and 6027 are not good!
 Just one example, here are the RAL 6027 and 6019 compared to the Celeste of the “Special” model 1970, the celeste in use from the mid-70s to the mid-80s (very tending to green) and the celescelestetial of the “X4” 1986, more tending to the blue.
The photo flattens the differences, however, it is clear that the 6019 is too light and green (RGB values 185,206,172), the 6027 too blue (RGB 126,186,181). The tone suitable for most of the Whites 70-80, read to the portable color meter Pantone Color Cue, has RGB values (here omitted) similar to the tint Pantone 556 finish M – “matte” (in the graph, only by reference, is shown the C – “coated” more suitable for a frame). |
|
 |
 |
 |
 |
| When compared to the bunches, the differences between the tones are obvious. they are also at the colorimeter with very different RGB values (R 185, 126, 105), G (206, 186, 158), B (172, 181, 132)
which correspond to a lighter color in the case of the 6019 (very green, G-36.6%) which has all three of the highest values (higher pyramid), a slightly darker color and with a lot of blue in the case of the 6027 (which has -60 points of red but 9 of blue), an even darker color in the case of Pantone 556C (which has -20R, -30G and well -60B) which among the 3 is the one with the highest percentage of green (G-40%). |
 |
Here are links to discussions on the topic:
https://www.facebook.com/RegistroStoricoCicli/posts/422437147903750
https://www.facebook.com/groups/Bicicletta.Bianchi.Epoca/permalink/1684213335014693
https://www.facebook.com/RegistroStoricoCicli/photos/a.384432981704167/1257958924351564
Thanks to Robert Cobcroft for his work on the X4: https://veloaficionado.com/blog/the-bianchi-x4-code