light brown stool with yellow speckles

Hi,  for several weeks now, with no other symptoms I have had stool that is a light brown with yellow speckles.  Almost looking like it would if you ate corn, but smaller.  I have not eaten corn!   From a distance therefore,  due to the many yellowish bits, the stool might appear yellowish.  But up close it is indeed brown - only a bit lighter than normal, but the speckles are yellow. (Not bright yellow, but yellowish)   My diet is strictly as follows:

1)  Red grapes
2)  Acme creamed Herring (3 12 Oz. jars per week.)
3)  LOTS of cereal, like honey niut cheerios and rice or multigrtain chex
4)  Soy Milk by Silk,  (No regular milk)
5)  Lots of cheese (unfortunately, when I eat grapes I also eat about 5 oz. of cheddar cheese.  4 times a week.
6)  Canned salmon and tuna.
7)  Raw Cashews,  a good deal of them, About 12 Oz. per week.

I was in Costa Rica for 3 months and drank a lot of water with fresh lemon  and coconut water.   Not sure when the stool started to appear lighter than normal.  I have been back in the states for 3 weeks with this diet as listed herein.

I have no other symptoms - so I just don't know.  I have heard gall stones may cause this - but I am not sure - as the symptom would be "yellow stool"  Mine is not yellow per se, just has the yellow bits, and the mains stool is light brown.

consistency, I estimate is normal to slightly softer than normal.   Bowel movements feel completely normal - no pain.

Thanks for your help.  Please write and call if possible.

Thank you!

Ken
917 741 3377