[DanBC]

That's a weird mis-characterisation of what it means to be colourblind. It's one of the discriminations that's still legal in England - electronics companies are allowed to not employ people with colourblindness because of the lack of suitable 'reasonable adjustments' and the need to have colour vision for a lot of electronic stuff.

Also, any resistors not in a pcb should be in a nice drawer with a neat label; any resistor in a circuit could give misleading values when multimetered because it's in a circuit.

[sliverstorm]

That's a weird mis-characterisation of what it means to be colourblind.

I thought male pattern colorblindness (far and away the most common type) simply means the inability to distinguish green from red, not total lack of color vision. Hence why I would expect you could still locate resistors with blue bands.

any resistors not in a pcb should be in a nice drawer with a neat label

"Should" being the operative word here. If that always happened, we wouldn't have bothered to give resistors identifying marks.

[DanBC]

> If that always happened, we wouldn't have bothered to give resistors identifying marks.

Yes we would, because we need to know what that resistor is when it's in a PCB. We can't measure it because it may be in parallel with other resistors.

> Hence why I would expect you could still locate resistors with blue bands.

Can you identify what the colours of this image should be? (Ignoring the massive clue in the filename.) :-p

(https://en.wikipedia.org/wiki/File:Rainbow_Deuteranopia.svg)

That's for a severe form of the most common form of color-blindnes.

(https://en.wikipedia.org/wiki/Color_blindness#Classification)

[sliverstorm]

Yes we would, because we need to know what that resistor is when it's in a PCB

Why couldn't we just label the resistor with silkscreen? We already decided labeling their drawer was better than labeling the resistor, so why not apply the same to the PCB? Easier to read silkscreen than color bands anyway, right?

Can you identify what the colours of this image should be

I said blue. Notice the blue is quite easy to spot in the image you linked. Of course it would still be a pain to try to find the 10k resistors by color, yes, I know that. But at least the color bands wouldn't be totally worthless.

[DanBC]

> Why couldn't we just label the resistor with silkscreen? We already decided labeling their drawer was better than labeling the resistor, so why not apply the same to the PCB? Easier to read silkscreen than color bands anyway, right?

Some resistors are labelled with silkscreen. Those resistors are expensive 1%, 0.1%, or 0.01%.

For run of the mill resistors it's cheaper to use colour coding. Also, when assembling a PCB it's good practice to keep the codes visible. That takes extra time for human operators. I don't know how machines do it for conventional components.

Labelling the PCB is important. There's a space marked R1, and a parts list telling us what R1 should be. There's a resistor in that space. How do we know what that resistor is? We read the color code, or the marking on the device.

There could have been a mistake at the resistor making factory, so we have a goods-in inspector who does some checking of the goods coming into the factory, and we buy from quality vendors and quality manufacturers. We hope the ISO 900x accreditation means something; we hope the certificates of conformity mean something.