fading blue colours in RGB mode go grey

Programming Questions

patsharkey

fading blue colours in RGB mode go grey

in Programming Questions • 2 years ago

A really basic question:

If I have this in a function

return color(0, 0, 100, VARIABLE_ALPHA); //dark blue

and gradually reduce VARIABLE_ALPHA to zero, the colour of the fill on the screen turns grey, colour (100) not white.

It doesn't do this when I do:

return color(0, 1, 100, VARIABLE_ALPHA); //dark blue

I can see I must be doing something dumb. Any ideas?

Many thanks

Replies(3)

cedrickie..

Re: fading blue colours in RGB mode go grey

2 years ago

how does your actual code look like? what and where do you fill with this color?
changing the value from 0 to 1 doesnt change the effect at least not in my test code.

void setup() {
size(255, 255);
}

void draw() {
background(100);

int VARIABLE_ALPHA = mouseX;
fill(color(0,1, 100, VARIABLE_ALPHA)); //dark blue
rect(0, 0, 255, 255);
}

patsharkey

Re: fading blue colours in RGB mode go grey

2 years ago

Try this:

The left box should (I think) be blue faded to white, the right box is green fading to white. As you move the mouse pointer slowly to the left of the window, when mouseX hits zero then the left box snaps into a grey colour but the right box is white. What's wrong with my logic?

void setup() {

size(255, 255);

}

void draw() {

background(255);

int VARIABLE_ALPHA = mouseX;

fill(color(0,0, 100, VARIABLE_ALPHA)); //dark blue

rect(0, 0, 100, 100);

fill(color(0,100, 0, VARIABLE_ALPHA)); //dark blue

rect(120, 0,100, 100);

}

PhiLho

Re: fading blue colours in RGB mode go grey

2 years ago

You should switch to HSB mode and progressively reduce the saturation part.

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