Get Hex triplet for color and real 256 RGB from diffuse Color using python

Question

as you know the RGB structure each parameter (red, green, and blue) defines the intensity of the color as an integer between 0 and 255., Actually, in Blender, you have that in sRGB, then any traditional convertion to HEX work BECAUSE the Hex in blender is GAMMA CORRECTED.

also in Documentation I can NOT get any reference about how get the HEX TRIPLE FOR COLOR CODE ...

how to get both with python?

UPDATE:

I want the hex value or how convert the hex to RGB

AS @dr.Sybren I thougth That was just a straight conversion of the bytes in RGB order converted to hexadecimal notation, and then tried some simple code as @tet_ii

context = bpy.context
obj = context.object

color_inferior= obj.material_slots['inferior'].material.diffuse_color


a = '#%02x%02x%02x' % (int(255.999 * pow(color_inferior.r, 1/2.2)),int(255.999 * pow(color_inferior.g, 1/2.2)),int(255.999 * pow(color_inferior.b, 1/2.2)))    

print(a)

testing the code I got:

also, I test other codes with the same or worst result:

https://stackoverflow.com/questions/3380726/converting-a-rgb-color-tuple-to-a-six-digit-code-in-python

then. Can I capture the value directly from blender without any convertion? or do a 100% accurate conversion?

Answer 1

This code adapted from devtalk.blender.org, convert color from blender standard active material to hex.

import bpy

#code by : brecht - devtalk.blender.org
def to_hex(c):
    if c < 0.0031308:
        srgb = 0.0 if c < 0.0 else c * 12.92
    else:
        srgb = 1.055 * math.pow(c, 1.0 / 2.4) - 0.055

    return hex(max(min(int(srgb * 255 + 0.5), 255), 0))

def toHex(r,g,b):
    rgb = [r,g,b]
    result = ""
    i=0
    while i < 3:
        val = str(to_hex(rgb[i]))
        val = val[2:]
        if len(val) == 1:
            val += val
        result+=val
        i+=1
    return result

ob = bpy.context.object
color_inferior = ob.active_material.diffuse_color

a = toHex(color_inferior[0],color_inferior[1],color_inferior[2])

print (a)

Answer 2

Try turn off color manager for display device:

bpy.context.scene.display_settings.display_device = 'None'

After, color circle give value 0xCA0001 for 0.791; 0.000; 0.003

Answer 3

To get something closer, I actually think that @Chau answer is relevant in the sense that we need to convert the colors from and back linear sRGB format (see this formula).

In fact I can somewhat get the same colors by doing:

import bpy

# run with exec(bpy.data.texts['convert.py'].as_string())

REPLACE_MAP = {
    '787859': 'B34CB3',
}

def srgb_to_linear(color):
    def color_conversion(c):
        if c <= 0.0404482362771082:
            return c / 12.92
        else:
            return ((c + 0.055) / 1.055) ** 2.4

    return list(map(lambda c: color_conversion(c), color[:3])) + [color[-1]]

def linear_to_srgb(color):
    def color_conversion(c):
        if c <= 0.00313066844250063:
            return c * 12.92
        else:
            return 1.055 * (c ** (1/2.4)) - 0.055

    return list(map(lambda c: color_conversion(c), color[:3])) + [color[-1]]

def hex_to_rgba(color_str):
    # supports '123456', '#123456' and '0x123456'
    (r,g,b), a = map(lambda c: c / 255, bytes.fromhex(color_str[-6:])), 1.0
    return (r,g,b,a)

def rgba_to_hex(color, alpha=False):
    rgba = ''.join(map(lambda c: "{:02x}".format(round(c * 255)), color))
    return rgba[:0 if alpha else -2].upper()

color = bpy.data.materials[-1].diffuse_color
(r,g,b,a) = color
linear = linear_to_srgb(color)
hex = rgba_to_hex(linear)
new_color = srgb_to_linear(hex_to_rgba(hex))

print('Initial color', r,g,b,a)
print('Linear', linear)
print('To hex', hex)
print('To color again', new_color)

color = hex_to_rgba("E95420")
(r,g,b,a) = color
print('from hex E95420', r,g,b,a)
print('to hex', rgba_to_hex(color))

Which results in:

>>> exec(bpy.data.texts['convert.py'].as_string())
Initial color 0.31398871541023254 0.533276379108429 0.8796223998069763 1.0
Linear [0.5960784331303468, 0.7568627293017685, 0.9450980405985859, 1.0]
To hex 98C1F1
To color again [0.31398871337571754, 0.5332764040105052, 0.8796223968878317, 1.0]
from hex E95420 0.9137254901960784 0.32941176470588235 0.12549019607843137 1.0
to hex E95420