Which of the following statements is incorrect?

Potassium amminetetracyanidonitrosoniumchromate(I)

having $\mu =1.73\mathrm{BM}$ has $d^{2}s{p}^3$ hybridization. 

${\mathrm{K}}_3\left[{\mathrm{AlF}}_6\right]+{\mathrm{BF}}_3\to {\mathrm{AlF}}_3+3{\mathrm{K}}_2\left[{\mathrm{BF}}_4\right]$

  $\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_3$ and $\left[\mathrm{Cu}{\left({\mathrm{NCCH}}_3\right)}_4\right] \left[{\mathrm{BF}}_4\right]$ both are coloured

$\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_4{\mathrm{Cl}}_2\right]\mathrm{Br}$ can show ionization isomerism with $\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_4\mathrm{ClBr}\right]\mathrm{Cl}$