phone systems, old and less-old

[Chuck Guzis]

On 9/19/19 9:56 AM, Kevin Monceaux via cctalk wrote:
> On Wed, Sep 18, 2019 at 09:05:07PM -0700, Chuck Guzis via cctalk wrote:
>  
>> 25 pairs, where
>>
>> White Red Black Yellow Violet for each "bank" and within each bank
>> Blue Orange Green Brown Gray
> 
>>From what I've heard and read, where a 25 pair cable is concerned, it's
> slate, not gray.

Yes, and Ma Bell had optional colors with names like "rose".

Regardless, what's the origin of the color scheme?  In other words, what
is the basis of the ordering?

Resistor color code follows (pretty much) colors as they occur in a
rainbow.  Evidently, Ma Bell doesn't believe in rainbows.

--Chuck