im 14 and I have recently noticed (2 months ago) that I have yellowy stuff that occasionally appears on my head of penis, I think it is smug a but It comes every day or so I have washed with mould soap and warm water for most days the past week or so but nothing happens. the head is also quite dry and a greyish red when not erect in areas but when a erect it is a normal red.
The grey colour is probably because the head is covered by your foreskin all the time.
It sounds like smegma under your foreskin.
Smegma is a natural, normal, harmless, and healthy substance. It is a mixture of exfoliated skin and skin oils. Smegma collects under the foreskin. It is normally white in color. Some people believe that smegma resembles cream cheese.
It can get irritating if it stays for a long time without being washed away, so it is good practice to wash under the foreskin periodically.
Accumulated smegma may get hardened and difficult to remove if it stays a long time such as under a foreskin that is not retracted. Olive oil has been recommended for softening and removing hardened smegma.
Since smegma is composed of exfoliated skin and skin exfoliation occurs continuously, smegma is continuously forming. You may expect to see more every day.