The report in the so-called Independent, sp, does not provide access to the actual MoJ data and I cannot find it readily.
Bland statements such as “…you're more likely to go to jail for first time offences if you're not white…” are a bit unhelpful without knowing what those first offences were. If it was possession with intent to supply large amounts of Class A drugs you are very likely to end up inside regardless of your previous - or your colour. If it was possession of a small quantity of class C for personal use for which you had previously received out-of-court disposals you are most unlikely to be imprisoned regardless of your previous - or colour.
I can only repeat what I have said about sentencing guidelines and in particular reiterate that those used by Magistrates are extremely tight, especially when determining whether a custodial or non-custodial sentence is imposed.
Have a look at some of them and see how a bench of Magistrates might manipulate them to impose a custodial sentence on a black person whilst not doing so for a white person convicted of an identical offence:
http://sentencingcouncil.judiciary.gov.uk/docs/MCSG_Update9_October_2012.pdf