I'm not very good at this, but I'll try...
1. DF dominant pied x normal will make SF dominant pied budgies
2. SF violet x normal will make half SF violet and half normal budgies and DF violet x normal will make SF budgies
3. 2 dark factors (e.g mauve) x 0 dark factors (e.g sky) will make 1 dark factor budgies (e.g cobalt)
4. Cobalt x cobalt will make half cobalt, 25% sky and the other 25% mauve
Hope this helps

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