How to change checkbox, checkbox ticks styles

Question

Here I have a multi-select list which looks like below.

But I am unable to change the CSS. this is the code so far I have tried, I am able to get outline colors, inside ticks am unable to see it.

input[type=checkbox], input[type=radio] {
    margin: 4px 0 0;
    margin-top: 1px\9;
    height: 16px;
    border-radius: 2px;
    line-height: normal;
    box-shadow: none;
    outline-offset: -1px;
    -webkit-appearance: none;
    width: 16px !important;
    margin: 5px;
     appearance:none;
     outline: 2px solid #455eab;
     font-size: 2em;
    
}
.form-check-input{
    width: 35px;
}
input[type="checkbox"]:checked ~ label::before {
    color: #455eab;
}

  <input class="form-check-input"[checked]=true type="checkbox">
  <input class="form-check-input" type="checkbox" >
  <input class="form-check-input" type="checkbox" >
  <input class="form-check-input" type="checkbox" >

Answer 1

Did you mean that ?

label {
  cursor: pointer;
  display: inline-block;
}
label input[type=checkbox] {
  display: none;
}
label input[type=checkbox]:checked + .cb-icon {
  background: #455DA7;
  border: 2px solid transparent;
}
label input[type=checkbox]:checked + .cb-icon::before {
  display: block;
}
label .cb-icon {
  width: 16px;
  height: 16px;
  display: block;
  position: relative;
  border-radius: 4px;
  border: 2px solid #455DA7;
  transition: all 0.5s ease;
}
label .cb-icon::before {
  content: "";
  top: 0px;
  left: 5px;
  width: 4px;
  height: 10px;
  display: none;
  position: absolute;
  transform: rotate(45deg);
  transition: all 0.5s ease;
  border-top: 0px solid transparent;
  border-right: 3px solid #fff;
  border-bottom: 3px solid #fff;
  border-left: 0px solid transparent;
}

<label>
  <input type="checkbox" name="" />
  <span class="cb-icon"></span>
</label>

<label>
  <input type="checkbox" name="" />
  <span class="cb-icon"></span>
</label>