Code colors in App inventor. RGB-opacity. Get color. Pick color.

These days I'm studying the colors in App Inventor.

I have posted tutorials about colors, but...  ummm are in Spanish, but maybe can help someone.

In Spanish RGB is (Rojo, Verde, Azul) RVA.

1. This about subtraction color (CMYK):

http://kio4.com/appinventor/20B_resta_colores.htm
p51B_suma_y_resta_colores.aia

2. In this app you pick color over image Canva and get RVA

If color is R= 240, V = 130, A = 80 then get Color = -1015216

Sub ConvertLongToRGB(ByVal Value As Long, R As Byte, G As Byte, B As Byte) 

R = Value Mod 256 

G = Int(Value / 256) Mod 256 

B = Int(Value / 256 / 256) Mod 256 

End Sub

Color = RVA - 16777216

http://kio4.com/appinventor/20C_decimal_rva.htm
p51C_decimal_rva.aia

3. In this tutorial you set R = 240, V = 130,  A = 80,  opacity = 255 and get Color =  4293952080

 N = A + (V + (R + (256 x opacidad)) x 256 ) x 256

http://kio4.com/appinventor/20D_separar_rva.htm
p51D_estudio_color.aia

4. This about opacity:

http://kio4.com/appinventor/20E_opacidad.htm
p51E_opacidad.aia

5. This is an app by Italo about RGBtoCMYK

RGB <-> CMYK conversion app

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Very complete study. And thanks for the mention!

You might find this app I made about fading interesting too: Canvas smooth fade to/from black (or any color)

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