120
Explanation:
total colours = 10
number of colours to be chosen = 7
We apply combination
The different color combinations possible:
[tex]^{10}C_7=\frac{10!}{(10-7)!7!}[/tex][tex]\begin{gathered} =\frac{10!}{3!7!}=\frac{10\times9\times8\times7!}{3\times2\times1\times7!} \\ =\frac{720}{6} \\ \text{= 120} \end{gathered}[/tex]The different color combinations possible is 120