How to change the input table cells color?

ok thanks 

last question

on the actual form . one line is white and next line biege

i want to change beige to blue but i don't see that one 

The code seems to be set with custom CSS code, so in order to change it you would need to inject this code to your form: 

.form-matrix-table tr:nth-child(2n) {

    background-color: blue;

}

This guide will help you injecting the code: https://www.jotform.com/help/117-How-to-Inject-Custom-CSS-Codes 

I hope this helps. 

this is what i see, what should it be

.form-matrix-table {
    max-width : initial !important;
}

.form-matrix-table {
    color : #000 !important;

No, simply copy the code I provided above and paste it on the CSS area of your form, to inject the code you may follow the provided guide, no matter where you add it, you can do it at the bottom or top of the existing injected code.