press the soles or palms....no colour changes?

[jojoki]

Hi just wanna ask.. when we press our soles or palm, the area will turn white n thn the red will come back.. but what happens when u press n there's just no changes?

I am asking for a friend, her toddlers feet is very pale and yellow, when i pressed his feet, no colour changes just very pale n yellow.

I cant recall but i think its some deficiency? issit iron or zinc??? anyone knows?