Text Color for different status Angular 6

You can use the below

<td *ngFor="let cell of row" 
  [ngStyle]="{'color': (cell.content === 'Busy') ? 'green' : (cell.content === 'overload') ? 'red' : (cell.content === 'idle') ? 'yellow' : ''}">{{cell.content}}
</td>

The condition should be on cell.content but not on row.content

You could make use of ngClass with some conditional check on the data while generating the row as follows,

<table class="table\" [ngClass]="modes\">
    <thead *ngIf="columns\">
        <tr>
            <th *ngFor="let col of columns"> {{col.content}} </th>
        </tr>
    </thead>
    <tbody>
        <tr *ngFor="let row of data">
            <td [ngClass]="{
                'busy' : cell.content == 'Busy',
                'idle' : cell.content == 'Idle'
                'overload' : cell.content == 'Overload'
             }" *ngFor="let cell of row"> {{cell.content}} </td>
        </tr>
    </tbody>
</table>

and you should also have a css for the above as,

.busy {
    background-color: green;
}

.idle {
    background-color: yellow;
}

.overload {
    background-color: red;
}