the max level 1 stat is 270, 255 when you look, but then it can add 15 points after that if the stat is at 255 (6.23% of the stat is either added or subtracted and you can go back and forth till its added) the max stat at max level after that is roughly 1.1 million without equips
final fantasy forum: http://s1.zetaboards.com/Final_Fantasy_Core/index/ please join if you like any final fantasy.
iirc the Yellow bars themselves cap at 40 points, and you can then boost a single stat up to 255 with the bonus points. To get the yellow stats to cap you need to up 67 points into each stat then take the character up to 9000ish (I just take them to 9999 .............) then when you do a second reincarnation the yellow bar will be maxed out at 40 points, so you would then put your 255 points into your desired stat, randomise it to get to 270 (best done with no equipment on so you can tell exactly what the stats are) and then finish the reincarnation. Once you take the character back up to 9999 he/she is done, unless if you want to change the character (eg make a Majin a MK) at which point you would need to repeate the "67 points in every stat" reincarnation to get maxed out yellow bars and then the 2nd, final reincarnation.