Colour Picker

Hex(#FFFFFF)

RGB(255, 255, 255)

RGB(100, 100, 100)

RGB(1.0, 1.0, 1.0)

HSV(360, 100, 100)

HSL(360, 100, 100)

OpenCV HSV(180, 255, 255)

Standard HSV/HSL use Hue in degrees and component percentages; OpenCV uses a scaled HSV form with H on 0-180 and S/V on 0-255.
Hold Shift while copying RGB (1.0 range) to append f suffixes (e.g. 1.0f,0.7f,0.7f).

I found that many colour pickers online only supported one format e.g. RGB out of 255, when I need different ones depending on the context. This aims to cover a few different formats.

Equations

For RGB normalised to $[0,1]$:

$$M = \max(R,G,B),\quad m = \min(R,G,B),\quad \Delta = M - m$$

HSV:

$$V = M,\qquad S_{\mathrm{HSV}} = \begin{cases} 0 & M = 0 \\ \Delta / M & M \ne 0 \end{cases}$$

HSL:

$$L = \frac{M + m}{2},\qquad S_{\mathrm{HSL}} = \begin{cases} 0 & \Delta = 0 \\ \dfrac{\Delta}{1 - |2L - 1|} & \Delta \ne 0 \end{cases}$$

Hue (used by both HSV and HSL):

$$H = \begin{cases} 60^\circ\!\left(\dfrac{G-B}{\Delta} \bmod 6\right) & M = R \\ 60^\circ\!\left(\dfrac{B-R}{\Delta} + 2\right) & M = G \\ 60^\circ\!\left(\dfrac{R-G}{\Delta} + 4\right) & M = B \end{cases}$$

HSV to RGB (with $H$ in degrees and $S,V \in [0,1]$):

$$C = VS,\qquad X = C\left(1 - \left|\left(\frac{H}{60^\circ} \bmod 2\right) - 1\right|\right),\qquad m = V - C$$ $$(R',G',B') = \begin{cases} (C,X,0) & 0 \le H < 60^\circ \\ (X,C,0) & 60^\circ \le H < 120^\circ \\ (0,C,X) & 120^\circ \le H < 180^\circ \\ (0,X,C) & 180^\circ \le H < 240^\circ \\ (X,0,C) & 240^\circ \le H < 300^\circ \\ (C,0,X) & 300^\circ \le H < 360^\circ \end{cases}$$ $$R = R' + m,\qquad G = G' + m,\qquad B = B' + m$$

In this picker, the large square is HSV $(S,V)$, so along the top edge $(V=1)$, $S_{\mathrm{HSV}}$ changes across the row while $S_{\mathrm{HSL}}$ stays at $100\%$ except at white.