Retirement Visa: Taxation liabilities (Colombo)

Hi I'm considering retiring to Sri lanka and while I can find clear info on the Govt. website on financial/documentation requirements, I couldn't find anything on whether I would be taxed on the US$ Protected content neeeded to be brought in to show financial capability to support myself nor any info on whether I could send out the excess (if any) on a periodical basis e.g. quarterly since I'm guessing with a quiet lifestyle, I might not spend this amount. Does anyone have any experience with this or know where I could get this answered?