Calculation of the specific rate constant (k)
We assume 1st order kinetics in hypochlorite and 1st order kinetics in the color. Putting this in the equation we get the following:
$$\frac{\text{d}[\text{Red}]}{\text{d}t} = -k\, [\text{Red}]^1 \, [\text{bleach}]^1 $$

Because you keep the concentration of bleach the same throughout the trial, you can write
$$k_\text{obs} = k\times [\text{bleach}]$$

Now, we can continue onwards as follows:
$$ k_\text{obs} = k \times [\text{bleach}] \Leftrightarrow k = \frac{k_\text{obs}}{[\text{bleach}]} = 0.0299~\mathrm{s^{-1}\; M^{-1}}$$