Array random color not generating

Question

I'm facing a problem where when I declare array of random colors. It shows random colors in a particle system on game start, but every time the game starts it shows white. I don't know why it happens, I didn't set white in my array.

public class A : MonoBehaviour 
{       
   Color[] colors = {
   new Color (170, 7, 107),
   new Color (58, 96, 115),
   new Color(81, 99, 149),
   new Color(71, 118, 231)
};

void start()
{
   GetComponent<ParticleSystem>().startColor =  colors[Random.Range(0, colors.Length)];
}

Fᴀʀʜᴀɴ Aɴᴀᴍ · Accepted Answer · 2015-12-01T08:48:42.610

3

In Unity, a color's ARGB components range between 0.0 to 1.0. So anything >1 will be considered 1 and so all the colors are white naturally.

To convert the colors, divide each component by 255. You can either do this yourself or leave it to the code itself. Also, don't forget to cast as float. Credit to @Masih Akbari for reminding me about this.

So, it should be :

Color[] colors = {
    new Color (170f/255, 7f/255, 107f/255),
    new Color (58f/255, 96f/255, 115f/255),
    new Color(81f/255, 99f/255, 149f/255),
    new Color(71f/255, 118f/255, 231f/255)
}

edited Dec 01 '15 at 08:48

answered Dec 01 '15 at 08:35

Fᴀʀʜᴀɴ Aɴᴀᴍ

6,131
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Damn, you got there before me! :p – Philip Rowlands Dec 01 '15 at 08:37
2

is unity just dived this as float? i feel you should dived this like this : `170f / 255` – dev-masih Dec 01 '15 at 08:44
@FarhanAnam thanks for your answer but if i add aplha in array than how can i give arguments of alpha and is there a way that i can generate strong random numbers in that array – Dec 01 '15 at 09:06
`255` is a *magic value*, `Byte.MaxValue`, IMHO, looks better; +1 – Dmitry Bychenko Dec 01 '15 at 09:12
@TimAllen for argb, it would be the same, except for an extra argument at the last for the alpha component like : `new Color(71f / 255, 0.3f, 0.2f, 1.0f)` – Fᴀʀʜᴀɴ Aɴᴀᴍ Dec 01 '15 at 09:59

score 1 · Answer 2 · answered Dec 01 '15 at 08:36

1

The reason for this is that colours are normalised in Unity. You have to divide each float you've set by 255 to get the actual value, e.g.

Color[] colors = {

    new Color (170/255, 7/255, 107/255),
    new Color (58/255, 96/255, 115/255),
    new Color(81/255, 99/255, 149/255),
    new Color(71/255, 118/255, 231/255)
};

answered Dec 01 '15 at 08:36

Philip Rowlands

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5
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`170/255` is... `0` (integer division), so you'll have `new Color(0, 0, 0)` in fact (`Black`) – Dmitry Bychenko Dec 01 '15 at 09:11
@DmitryBychenko How to fix that what does mean 255 is magic value – Dec 01 '15 at 09:12
@Tim Allen: `170f/255` or `170/255f` or `(float) (170.0/255.0)` etc. – Dmitry Bychenko Dec 01 '15 at 09:13
1

@TimAllen [Magic Number](http://stackoverflow.com/questions/47882/what-is-a-magic-number-and-why-is-it-bad) is nothing but a number used directly instead of first declaring it as a constant. It will **not** make the code malfunction but it is a better practice not to use magic numbers, – Fᴀʀʜᴀɴ Aɴᴀᴍ Dec 01 '15 at 10:01

dev-masih · Answer 3 · 2015-12-01T08:46:47.700

0

Your Color values must be between 0 to 1. everything after 1 is considered white.

Don't forget to cast your number as a float

edited Dec 01 '15 at 08:46

answered Dec 01 '15 at 08:37

dev-masih

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Array random color not generating

3 Answers3