Bearded dragon stress marks from coloured bulbs

Those constant stress marks are a direct response to the coloured bulbs — blue and green heat bulbs distort a bearded dragon's light perception and cause chronic low-grade stress, on top of providing zero UVB, which at one year old means your dragon has likely been building up a UVB deficit that can quietly lead to metabolic bone disease. Bad lighting is genuinely the most common husbandry mistake with bearded dragons, and coloured bulbs are one of the worst offenders because they look like they're doing something useful. To point you in the right direction: what size is the enclosure, and how is it set up — do you have a separate basking spot and a cooler end?

Good that you've removed them — that's the right first move. A 4x2x2 is a solid adult-sized enclosure and gives you room to do this properly. The absence of UVB is the more urgent issue right now. At one year old your dragon is still growing, and without UVB they can't synthesise vitamin D3, which means calcium can't be absorbed regardless of how well you're feeding. How is the dragon's mobility — are they moving around normally, and are their limbs and jaw looking straight and normal? I want to know if there are any signs of MBD already developing before recommending exactly what to get.

That's reassuring on the MBD front — catching this at one year with no visible skeletal signs means you're in a good position to correct it before damage sets in. The short basking sessions are likely connected to the stress and disorientation from the previous setup; once the lighting is right you should see that improve. For a 4x2x2, you need a T5 HO UVB tube running at least two thirds of the enclosure length, and for a one-year-old dragon the correct output is a 12% UVB tube. The product I'd recommend is the Arcadia Dragon Lamp D3+ 12% T5 HO — it comes in a 39W 865mm size that works well for your enclosure, and Arcadia is the most trusted brand for reptile UVB in the UK. Pair it with a separate halogen flood for basking — a 50W Arcadia Halogen Flood Lamp — and aim for a basking surface temperature of 40–42°C measured with a temperature gun, not a stick-on dial. Mount the T5 inside the vivarium at around 30–40cm from the basking surface for correct UV Index exposure.

In your dragon's case the stress marks are almost certainly environment-driven rather than a sign of disease. Bearded dragons are extremely sensitive to light quality — coloured bulbs alter the wavelengths they perceive and create a state of persistent unease, which shows as permanent stress patterning. Once you have the Arcadia D3+ 12% T5 HO running on a proper 10–12 hour daylight cycle with a clean white basking lamp, most dragons settle down within one to three weeks. If the marks persist beyond a month with correct lighting, that would be worth a vet check to rule out parasites or an underlying issue — but based on what you've described, I'd expect a clear improvement fairly quickly. Get the UVB in first, that's the priority.

Just the bulbs and a temperature gun if you don't have one — everything else you've described sounds fine. The key ongoing thing to know is that T5 UVB tubes degrade before they visibly dim — replace the Arcadia D3+ every 12 months even if it still appears to be working, because the UV output drops significantly before the light does. Set a calendar reminder now. Keep the photoperiod consistent at around 12 hours on and 12 off, avoid any coloured or red night bulbs if you want to add nighttime heat — a ceramic heat emitter is the correct option for that. You're in a good position; this is a fixable situation and your dragon is young enough to come through it without lasting effects.