At low pH levels, both chlorine and bromine can appear in a pool as undissolved gasses. With bromine -- which you have because of the bromide -- the pH doesn't have to be nearly as low as it does with chlorine. In blue pool water, orange-ish bromine gas could easily look yellowish green.
To avoid this, keep working to raise the pH AND chlorinate using small repeated doses of bleach in the skimmer, rather than large doses of anything in the pool.
Shocking -- adding a bunch of chlorine of any kind -- is to be avoided till you get the pH at 7.0 or higher. But, don't go higher, because with all that copper, you'll start staining things like crazy.
You can use bleach for any chlorinating purpose in a pool.
By the way, I don't generally like to use metal control agents, but in your case, it might avoid some trouble if you can put a dose of metal control liquid in the pool. It's only a temporary solution, but it might give us time to get control of the pool before we start having to work on removing the copper. If you can get HEDP (probably no way for you to know, though) it will also help protect your heater from further damage.
PoolDoc.
PS. It's just curiosity, but do you know how your pH got so low?
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