Calculation of color tones

Question

I have the following problem.
I have a base color with a pair of different shades of this color.

Example:

• Main color: # 4085c5
• Shadow: # 005cb1

Now I have a different color (say # d60620), but there are no shades of it. From the color, I would like to calculate shades that have a similar difference, like the colors mentioned in the first paragraph.

At first I tried to calculate the difference between the RGB elements and apply them to the second color, but the result was not what I expected. Than I tried to convert the color to HSV , indicating the saturation value and applying the difference to the second color, but again the resulting color was still strange.

The formula was something like this: (HSV (BaseColor) [S] - HSV (Shade) [S]) + HSV (SecondColor) [H]

Does anyone know how this problem can be solved? I know that I am doing something wrong, but I do not know what. :)

Answer 1

There are two ways to darken color:

• Subtract an equal amount from R, G, B. This increases saturation. Obviously, you can only subtract the mount equal to the smallest of the values ​​of R, G, B.
• Multiply R, G, B by a value less than 1.0. This leaves the saturation more or less intact.

Similarly, there are two ways to lighten color:

• Add an equal amount to R, G, B. This reduces saturation.
• Multiply R, G, B by a value greater than 1.0. This increases the brightness of the color and, consequently, the apparent saturation.

Your example seems to have done both - subtracting 0x40 from each value and multiplying by 1.33.

Using your second color, we can subtract 06 from each result in # d0000a, but it's not dark enough. Multiplying by 0.735 results in # 990013.

Answer 2

Your first two colors have an “H” (hue) value of 209 and different meanings for “S” and “V”.

This general shade is what defines the second color as the “shade" of the first color.

To find alternate hues for your third color, use the RGB to HSV conversion to find its hue, change its S and V values ​​as desired, and then convert it back to RGB.