how to make the render on vue2 equals to the render on vue3

I have the same code, but if I run it on vue2/vuetify2 the render will be:

If I run it on vue3/vuetify3 I get:

The color is not black anymore, “informativa privacy” is red and the “Entra nel sito libero” is blue, and the icon are different too;

this is my code:

<template>
    <v-container>
      <v-row>
        <v-col>
          <v-flex>
            <v-card>
              <v-card-title  >
                <div>Informazioni</div>
              </v-card-title>
              <v-card-text>
                <li>
                  <router-link  
                     :to="'/privacy_information'"
                    >Informativa Privacy</router-link
                  >
                </li>
                <li>
                  <a href="https://www.libero.it/" target="_blank"
                    >Entra nel sito libero</a
                  >
                </li>
              </v-card-text>
            </v-card>
          </v-flex>
        </v-col>
        <v-col offset="4">
          <v-flex >
            <v-card >
              <v-card-title>
                <div>Seguici su</div>
              </v-card-title>
              <v-card-text>
                <v-btn
                  href="https://twitter.com/liberoGroupIT"
                  target="_blank"
                  class="ma-2"
                  tile
                  large
                  color="#1DA1F2"
                  icon
                >
                  <v-icon >mdi-twitter</v-icon>
                </v-btn>
                <v-btn
                  href="https://www.linkedin.com/company/libero-italia"
                  target="_blank"
                  class="ma-2"
                  tile
                  large
                  color="#2867B2"
                  icon
                >
                  <v-icon large>mdi-linkedin</v-icon>
                </v-btn>
                <v-btn
                  href="https://www.facebook.com/liberoGroup/"
                  target="_blank"
                  class="ma-2"
                  tile
                  large
                  color="#3C5A99"
                  icon
                >
                  <v-icon large>mdi-facebook</v-icon>
                </v-btn>
              </v-card-text>
            </v-card>
          </v-flex>
        </v-col>
      </v-row>
    </v-container>

</template>

I’ve tried to add almost any class, try to set color as in

<router-link 
                    color="black"
                     :to="'/privacy_information'"
                    >Informativa Privacy</router-link
                  >

but nothing will change, and no idea how to go futher!!! the icon are the same, no css is specified.

How I can render the color black in vue3 and How I can rendere the icon in the same way (with background trasparent)