if u mean half brown and half white, yep thats normal.
very loose smelly stools indicate parasites, when mine had worms i saw wriggly worms.
by smelly, it will smell like poo, but shouldnt bring tears to ur eyes and clear a room
mine poo every day, when they were 6 months old they'd generally go twice a day.
mealies are high in fat and the chitin shell can impact (constipate) them, theyre not recommended in large amounts.
woodies are a good feeder to add variety,....at 6 months mine were eating about 30-60 crickets a day if i remember correctly,..they needs lots of protien to grow,..
too many vitamins arent good, beardies can overdose on them. they shouldnt get anything that contains vitamin a.
calcium should be given more often than vitamins, so its recommended you get a good calcium supplement so you have more control,...
repcal (pink label) is a good one, no added phosphorus but added vitamin D3.
D3 helps process the calcium they eat into a form they can use, but doesnt eliminate the need for a UVB light....
http://www.herpshop.com.au/
(click on health and sanitation to see the good supplements)