Exemplo de tema custom

ng-dialog.less

// ========================================================================
//   Component: ngdialog.less
// ========================================================================

.ngdialog {
  z-index: 9001 !important;
  &.ngdialog-theme-default {

    .ngdialog-content {
      background-color: #fff;
      border-radius: @border-radius-base;
      font-family: inherit;
      font-size: inherit;
      line-height: inherit;
    }

  }
}


@keyframes zoomIn {
  from {
    opacity: 0;
    transform: scale3d(.3, .3, .3);
  }

  50% {
    opacity: 1;
  }
}

@keyframes zoomOut {
  from {
    opacity: 1;
  }

  50% {
    opacity: 0;
    transform: scale3d(.3, .3, .3);
  }

  to {
    opacity: 0;
  }
}


.ngdialog.ngdialog-theme-flat {
  z-index: 2147483647 !important;
  padding-bottom: 100px;
  padding-top: 100px;
  -webkit-perspective: 1300px;
  -ms-perspective: 1300px;
  perspective: 1300px;
  -webkit-perspective-origin: 50% 150px;
  -ms-perspective-origin: 50% 150px;
  perspective-origin: 50% 150px;
}

.ngdialog.ngdialog-theme-flat .ngdialog-overlay {
  background: transparent;
}

.ngdialog.ngdialog-theme-flat.ngdialog-closing .ngdialog-content {
  -webkit-animation: zoomOut .5s;
  animation: zoomOut .5s;
}

.ngdialog.ngdialog-theme-flat .ngdialog-content {
  -webkit-animation: zoomIn .5s;
  animation: zoomIn .5s;
  background: #fff;
  color: #444;
  border: 3px solid @brand-green;
  border-radius: 7px;
  margin: 0 auto;
  max-width: 100%;
  position: relative;
  -webkit-transform-style: preserve-3d;
  -ms-transform-style: preserve-3d;
  transform-style: preserve-3d;
  width: 600px;
}

.ngdialog.ngdialog-theme-flat .ngdialog-close {
  cursor: pointer;
  position: absolute;
  right: 0;
  top: 0;
}

.ngdialog.ngdialog-theme-flat .ngdialog-close:before {
  background: @brand-green;
  color: #fff;
  display: block;
  font-family: "Helvetica Neue",sans-serif;
  font-size: 1em;
  font-weight: 100;
  height: 1.25em;
  line-height: 1px;
  overflow: hidden;
  padding-top: .5em;
  right: 0;
  text-align: center;
  text-indent: 1px;
  top: 0;
  width: 1.25em;
}

.dialog-content {
  padding: 2em 2em 3em;
}

/* iPads (landscape) ----------- */
@media only screen
and (max-width : 1024px) {
  .ngdialog.ngdialog-theme-flat .ngdialog-content {
    width: 400px;
  }

  .dialog-content {
    md-tabs {
      md-content {
        max-height: 250px;
      }
    }
  }
}


/* Desktops and laptops ----------- */
@media only screen
and (max-width : 1024px) {
  .ngdialog.ngdialog-theme-flat .ngdialog-content {
    width: 400px;
  }
}

@media only screen
and (min-width : 1024px)
and (max-width : 1823px) {
  .ngdialog.ngdialog-theme-flat .ngdialog-content {
    width: 550px;
  }
}


/* Large screens ----------- */
@media only screen
and (min-width : 1824px) {
  .ngdialog.ngdialog-theme-flat .ngdialog-content {
    width: 600px;
  }
}

@media only screen
and (max-height : 800px) {
  .dialog-content {
    md-tabs {
      md-content {
        max-height: 250px;
      }
    }
  }
}

@media only screen
and (min-height : 801px)
and (max-height : 1080px) {
  .dialog-content {
    md-tabs {
      md-content {
        max-height: 320px;
      }
    }
  }
}

@media only screen
and (min-height : 1080px) {
  .dialog-content {
    md-tabs {
      md-content {
        max-height: 400px;
      }
    }
  }
}