Can you get cyclizine, hydroxyzine, meclizine, or close chemical relatives? They make opioids in the various amidone-methadol families of open-chain synthetics work better, as do benzodiazepines like diazepam, nitrazepam and so forth . . .
I've noticed the pink colouration when monking around with MS Contin/MST Continus/Vendal Retard and Kadian too and several of the methods for extracting Miss Emma from whole opium -- I think pinkness also happens to be very pale brown . . . Whether the pinkness in the former comes from morphine itself or a close modification of the morphine salt in question, maybe an intermediate in decomposition such as Morphine-N-Oxide, pseudomorphine or others, I am not sure.
It may be relevant that a similar colour arises from a similar morphine HCl → DHM → diacetyldihydromorphine process as well, so that opens up some possibilities and makes others less likely . . . the fact that poppy and poppy seed derivatives and opium are often dark brown and there is indeed dark pink or reddish smack in some locales makes one wonder . . . Industrial and improvised processes involving morphine and smack both have a penultimate step of using activated charcoal to come up with a white powder, so the pink/brown here could be either an inactive congener or a product in the same range of potency as morphine.
It may be relevant here that hydromorphone and oxymorphone, metopon, and oxycodone injection ampoules and phials can develop a slight amber colouration over long periods especially if exposed to light . . . I don't recall seeing nicomorphine, dihydromorphine, diacetyldihydromorphine in ampoules or dibenzoylmorphine in test tubes turning this colour, but maybe it takes a long time to develop . . . There are spontaneous changes caused by hydrolysis and light exposure in solutions of smack used medicinally which is why injectable diamorphine is, at least on the Continent, usually seen in dry ampoules which are reconstituted right before use with saline, distilled water, or saline-based injection fluid of other agents which make the smack work better and reduce side effects, such as other preliminary drugs in a general anaesthesia situation, infusions for malaria prophylaxis, anaemia and other afflictions, or when used for pain, maintenance and so on . . . then it is commonly adjuncts like pheniramine, dexchlorphenamine, hyoscine/scopolamine, tripelennamine, hydroxyzine, phenindamine, orphenadrine, conservative doses of stimulants &c &c
Maybe it comes from one of the other ingredients (a flash of heat or somewhat longer application of milder heat make the carnauba wax, any plasticisers and other waxy items brittle and more prone to separate from the rest of the solution and float; the other sine qua non ingredient for homebake seems to destroy the waxiness outright and yield, directly from the hydrochloride, sulphate, tartrate or other salt, a black, grey, or brown dusty, dry solid like you say which usually requires a mortar & pestle (if not a hammer) which, especially with isotonic saline, becomes a very clear brown solution and insolubles which bear more resemblance to sand (or coal dust) than the waxy stuff that floats on top or fills the vessel for heating when no prep work is done. The colouring on the tablet contains 3 to 11 per cent of the morphine dose and is very messy so it should be removed in such a way that one can drink the coating and work with white tablets . The salt content of isotonic or hypertonic saline (like 1.8 per cent; 5 per cent may be overdoing it, 0.45 per cent (4.5 per mille) works well too) in particular also helps the separation of wax.
