Buildings > Raeli Oven > Color Map

You can help!

We need your help gathering data for investigating Raeli tile colour distribution in Egypt. Read the section, "Predicting Tile Colours" below, and contribute information on ovens you run. Or go to more detailed instructions on how to help.

Why do we want this?

• it could help locate ovens likely to produce colours not found in ANY known oven.
• ... or colours you, individually, don't already have access to.

and once we have enough information on where to find ovens that can produce any given colour, we can look to formulas for when that colour will be produced at that oven. That is, you might know, even before the oven is placed, how long into the baking cycle it will produce a given colour.

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Raeli Oven Colours

A Raeli Oven produces colors which are fixed at build time as a function of location.

Each oven has two characteristics to its colour: hue and saturation. Hue defines the relative strengths of red, green, and blue in the oven; one oven might be primarily cyan, while another might be red with a hint of yellow, for instance. Saturation defines how 'bright' the overall colours are, in terms of the distance of the oven's colours from gray. These two values are related to location in a pattern that is not yet fully understood. In general, however, ovens with grayer saturation values are considered to be less valuable, as they have reduced colour variation. Each oven will, when fired, traverse a line of colours starting with white and ending with black approximately 140 minutes later, with the rest of the colours along the way selected by the hue and saturation values.

In order to facilitate tile trade and science, available colours and suppliers should provide information on what colours they have, as well as any information which might help us understand what fixes the tile colours.

Each Oven can be defined by two numbers, it's Saturation and Hue. These remain fixed throughout the entire range of colours. To work out your Oven's Saturation and Hue, use a colour picker such as Autohotkey's Windowspy, and enter the colour values from a colour in the middle of your range into the "edit-colours, define custom colours" of MS paint or the Gimp. Please then add your Saturation and Hue here.

There are two different definition of saturations, one of which is not held constant by raeli ovens. The Gimp uses the one that is not constant. You can see if you're using the wrong one by testing half an hour into a run, and then again an hour into a run, and seeing if it gives the same saturation value. If you get the wrong one or don't want to risk it, you can compute the saturation (and hue, as well) the right way from the red-green-blue values using the formulas from here.

For purposes of the science of getting raeli ovens figured out, a list of colours your oven can make it pretty useless, as it's far too imprecise. If you'd like to help with the science, getting your hue and saturation values and the coordinates of your oven for a relative handful of ovens would probably be sufficient. The colours that an oven can make could readily be reproduced from the hue and saturation values, but the converse isn't possible.

Predicting Tile Colours

Quizzical has provided the attached spreadsheet, which is further described in the forum at Raeli Oven Theory. The spreadsheet allows you to sample the RGB values for a tile, preferably a tile near the middle of the luminance sequence as that's where the hue and saturation are the most dominant, and convert that RGB value into a Hue and Saturation. As the Hue and Saturation is a given for a particular oven, iterating the Luminance therefore allows you to completely define the colour sequence for an oven.

We would like to collect data that is accurate enough to corrolate the Hue and Saturation with the coordinates of the existing ovens, and then create a model that indicates the available locations for any desired colour. Your help would be appreciated.

A half dozen samples from a colour swatch taken about 70 minutes into the baking cycle, where White and Black have the least influence, is the most accurate way to characterize an oven, but you can also back into the likely value when the colours are known. In the following table, the values in italics are hypothetical and we just went through and added an "*" to make the modeled data more obvious.

See also

• Raeli Tiles trade list for a list of people who have tiles of various colours available for trade either immediately or by special order.
• Raeli tiles for a complete list of all colours of Raeli tiles known to have existed in Egypt in times past.
• Known Map - the list of all known ovens. (Colours not included.)
• Map of public raeli ovens
• The relationship between the two colour spaces is defined and illustrated at HSL_color_space and RGB_color_model.
• Reported Colors indicates the number of ovens that are reporting each colour, which is a rough indicator of colour rarity, and presents those colours sorted by Hue, Satuation, and Luminance, Saturation, and Hue so that you may more easily visualize which colours mask each other. Note, in particular, the colors near 0.50 Luminance as White and Black have the least influence on those colors, and there are a lot of exclusive choices.

Colour Table