just recently tested mine in marquis a few times, first time fizzed and turned white with a green tint and second time fizzed and turned completely white
Was that the same batch turning different colors? o_o
In any case
MARQUIS IS NOT SUFFICIENT TO TELL MDAI FROM COMMON CHEMICALS USED IN FAKE MDAI.
Pure, super clean, MDAI will not turn Marquis a color - however, MDAI that pure is very rare, and vendors frequently ship UK-illegal cathinones* as MDAI - and many cathinones also do not change the color of marquis.
MDAI will turn mecke brown, while the cathinones which don't produce color with marquis will not.
Also, smell the MDAI. Clean MDAI, if it has any smell at all, will smell vaguely like root beer. If it smells like a cathinone (I assume you know what meph and it's ilk smell like - all the cathinones smell pretty much the same), you know for sure it's either fake, or has been cut with a cathinone (both of which are very common, unfortunately)
*Cathinones that won't color marquis are basically any cathinones other than methylone, butylone, and MDPV. Mephedrone, 3-FMC, buph, ethcat, 4-EMC, 4-MEC, 3,4-DMMC and the like all produce almost no color change in response to Marquis/Mecke, and a faint yellow to Mandellin.