What substances in ash may create a green colour and are also soluble in water?

I have an ash that is high in $\ce{K2O}$ ($ \gt 30 \text{%}$), $\ce{SiO2}$ ($ \gt 10 \text{%}$) and $\ce{CaO}$ ($ \gt 10 \text{%}$), with $\ce{P2O5}$ ($5 \text{%}$) and $\ce{MgO}$ ($3 \text{%}$) also present. When the ash is heated to above $700^\circ \pu{C}$ for $16$ hours for decarburizaton, a color change is observed, from beige to a shade of turquoise, which at higher temperatures ($1300^\circ \pu{C}$ for $10$ mins) becomes a deep shade of green during cooling (the green substance appears to be condensing through the sample).


Whatever substance that is causing this green color appears to be inhibiting melting within the sample (melting temperature should be around $1200^\circ \pu{C}$, according to ash fusion testing), and is soluble in water. I've found through XRD that the ash has significant peaks that correspond to $\ce{KCl}$ in the form of sylvine, but I'm not sure that there is enough chlorine to cause such a deep color change, or that it could cause the color change at $700^\circ \pu{C}$.


So, my question is, does it seem possible that $\ce{KCl}$ is what is causing this color change, and are there other possible candidates that I should test for? (For instance, I've read that potassium manganate will dissolve in water, resulting in a green color too, but I'm not sure how feasible that is).


