Thanks Sir.
1. The yellowish subapical/postdiscal step-up bands running from space R5 to space CuA2 for the male of T. colon have yellowish scaling along the vein to the margin like a radar antennae stretched towards the margin of the upper forewing (Ref.: Indenfying Butterflies, Hong Kong Lepidopterists' Society, Page No.: 165
2. Upf outer edge of discalspots deeply excavated and continued along veins to termen in male. (The indentification of Indian butterflies by Evans., Page no.: 263)

But in this species only Spot 2 & 3 continued along veins towards termen.

Regards,
Rajib Dey