I Have the original Chord Signature now and have owned Nordost SPM - very high end (their original reference cable) older cable from them similar cost £500 1/2 metre and blue heaven - interconnects
You will struggle to get a Signature brand new for your budget - the Signet is the old signature cable config and the signature plus has a new config but is approx £600 so you may want to look at the Signet.
The Chord Signature original (signet now) is a stunning cable, I feel it just lets your system properly through without adding or more importantly taking away, changing anything. I say this because as I have changed my system components the sound has always changed and I have tried the cable in other systems friends etc that are similar to mine and it sounded different again. There has not been the similar characteristic to the sound that you will get with lesser / other cables if that makes sense, where the sound is shaped in a certain way i.e. good bass, narrow sound stage, compressed mids
With Nordost SPM and blue heaven that wasnt 100% the case - both very good cables. Blue Heaven sounded like a scaled down version of the SPM - lacking bass and general weight but very airy clean sound - this type of sound you might like. The SPM was very full on, big and bold with excellent bass, excellent mids, much better cable than a Chord Chorus for example, very airy sound but lacked the focus, realism and cleaness of the Chord Signature. The Chord Signature had all the positive traits of the Nordost SPM
I have not heard the purple flair but it seems to come into their range between Blue Heaven and Red Dawn, I would say the original Chord Signature or current Chord Signet would outperform it if it outperforms an albeit older but higher end cable in the SPM (£1000 a metre new) I have never found the Signature to sound too bright, I did at times with Nordost cables - I was running the Nordost with Russ Andrews 8TC - copper cable, then QED Revelation speaker cables, that balanced better I thought. Russ Andrews is a clinical sound - again you might liek this as it reminds me of the Cyrus CD Player I owned CD6S
I also think to get the best of Nordost you need to use their speaker wire as well - then again that is what all manufacturers say
I now run Chord Sig Interconnects with Chord Epic Speaker Cable - I think this works extremely well
If you meant speaker wires by your question please ignore my comments - they were all based on my interconnects experience