need to change the color of submit button if input has some value

[vinothini_2021]

i have form., in that form i have input field and confirm button., i just want to change the confirm button color if input has some value otherwise the button will be normal., i have tried many method but didnt work.. please help me to fix that problem

[AndrisP]

Use CSS e.g.

input[type="button"][value="one"] {
    background: blue;
}
input[type="button"][value="two"] {
    background: red;
}